INST 262 (DCS and Fieldbus), section 2 Lab Automatically ...

Lab 

INST 262 (DCS and Fieldbus), section 2 

Automatically-controlled process: Questions 91 and 92, completed objectives due by the end of day 

4 

Exam 

Day 5 

Specific objectives for the “mastery” exam: 

• Build a circuit to energize an electromechanical relay (question 93) 

• Identify proper controller action (direct or reverse) for a given process 

• Determine the effect of a component fault or condition change in an automatically-controlled process 

• Identify specific instrument calibration errors (zero, span, linearity, hysteresis) from data in an “As- 

Found” table 

• Solve for a specified variable in an algebraic formula 

• Determine the possibility of suggested faults in a 4-20 mA loop circuit given measured values (voltage, 

current), a schematic diagram, and reported symptoms 

• INST231 Review: Sketch proper wire connections for sourcing or sinking PLC I/O points 

• INST240 Review: Determine suitability of different level-measuring technologies for a given process fluid 

type 

• INST251 Review: Identify the graphed response of a controller as being either P, I, or D 

Day 1 

Recommended daily schedule 

Theory session topic: DDC, DCS, and SCADA system configuration 

Questions 1 through 20; answer questions 1-10 in preparation for discussion (remainder for practice) 

Day 2 

Theory session topic: Instrument calibration 


Day 3 

Theory session topic: Instrument calibration (continued) 


Day 4 

Theory session topic: Review for exam 


Feedback questions (81 through 90) are optional and may be submitted for review at the end of the day 

Day 5 

Exam 

1

INSTRUCTOR CONTACT INFORMATION: 

Tony Kuphaldt 

(360)-752-8477 [office phone] 

(360)-752-7277 [fax] 

tony.kuphaldt@btc.ctc.edu 

DEPT/COURSE #: INST 262 

Course Syllabus 

CREDITS: 5 Lecture Hours: 22 Lab Hours: 70 Work-based Hours: 0 

COURSE TITLE: DCS and Fieldbus 

COURSE OUTCOMES: Commission, analyze, and efficiently diagnose instrumented systems 

incorporating networked control platforms (DCS, Fieldbus, wireless). 

COURSE DESCRIPTION: This course teaches the basic principles of distributed instrumentation, 

including distributed control systems (DCS), FOUNDATION Fieldbus instruments, and wireless field 

instruments. Pre/Corequisite course: INST 260 (Data Acquisition Systems) Prerequisite course: 

MATH&141 (Precalculus 1) 

COURSE OUTLINE: A course calendar in electronic format (Excel spreadsheet) resides on the Y: 

network drive, and also in printed paper format in classroom DMC130, for convenient student access. This 

calendar is updated to reflect schedule changes resulting from employer recruiting visits, interviews, and 

other impromptu events. Course worksheets provide comprehensive lists of all course assignments and 

activities, with the first page outlining the schedule and sequencing of topics and assignment due dates. 

These worksheets are available in PDF format at http://openbookproject.net/books/socratic/sinst 

• INST262 Section 1 (Feedback control systems): 4 days theory and labwork 

• INST262 Section 2 (DDC and DCS platforms): 4 days theory and labwork + 1 day for 

mastery/proportional Exams 

• INST262 Section 3 (FOUNDATION Fieldbus): 4 days theory and labwork 

• INST262 Section 4 (Wireless instrumentation): 4 days theory and labwork + 1 day for 

mastery/proportional Exams 

2

STUDENT PERFORMANCE OBJECTIVES: 

• Without references or notes, within a limited time (3 hours total for each exam session), independently 

perform the following tasks. Multiple re-tries are allowed on mastery (100% accuracy) objectives, each 

with a different set of problems: 

→ Build a circuit to energize an electromechanical relay given a switch and relay both randomly selected 

by the instructor, with 100% accuracy (mastery) 

→ Build a HART process transmitter circuit and use a HART communicator to alter transmitter 

parameters with 100% accuracy (mastery) 

→ Identify proper controller action for a given process with 100% accuracy (mastery) 

→ Predict the response of an automatic control system to a component fault or process condition change, 

given a pictorial and/or schematic illustration, with 100% accuracy (mastery) 

→ Determine proper AI block parameters to range a Fieldbus transmitter for a given application, with 

100% accuracy (mastery) 

→ Calculate power loss (decibels versus watts) for a radio signal, with 100% accuracy (mastery) 

→ Calculate instrument input and output values given calibrated ranges, with 100% accuracy (mastery) 

→ Identify specific instrument calibration errors (zero, span, linearity, hysteresis) from data in an “As- 

Found” table, with 100% accuracy (mastery) 

→ Solve for specified variables in algebraic formulae, with 100% accuracy (mastery) 

→ Determine the possibility of suggested faults in a simple circuit given measured values (voltage, 

current), a schematic diagram, and reported symptoms, with 100% accuracy (mastery) 

→ Sketch proper power and signal connections between individual instruments to fulfill specified control 

system functions, given pictorial and/or schematic illustrations of those instruments 

• In a team environment and with full access to references, notes, and instructor assistance, perform the 

following tasks: 

→ Demonstrate proper use of safety equipment and application of safe procedures while using power 

tools, and working on live systems 

→ Communicate effectively with teammates to plan work, arrange for absences, and share responsibilities 

in completing all labwork 

→ Construct and commission an automatically-controlled process using a PID controller 

→ Generate an accurate loop diagram compliant with ISA standards documenting your team’s control 

system 

→ Commission and decommission a FOUNDATION Fieldbus instrument 

• Independently perform the following task on a functioning PID control system with 100% accuracy 

(mastery). Multiple re-tries are allowed with different specifications/conditions each time): 

→ Diagnose a random fault placed in another team’s control system by the instructor within a limited 

time using no test equipment except a multimeter, logically justifying your steps in the instructor’s 

direct presence 

3

METHODS OF INSTRUCTION: Course structure and methods are intentionally designed to develop 

critical-thinking and life-long learning abilities, continually placing the student in an active rather than a 

passive role. 

• Independent study: daily worksheet questions specify reading assignments, problems to solve, and 

experiments to perform in preparation (before) classroom theory sessions. Open-note quizzes and work 

inspections ensure accountability for this essential preparatory work. The purpose of this is to convey 

information and basic concepts, so valuable class time isn’t wasted transmitting bare facts, and also to 

foster the independent research ability necessary for self-directed learning in your career. 

• Classroom sessions: a combination of Socratic discussion, short lectures, small-group problem-solving, 

and hands-on demonstrations/experiments review and illuminate concepts covered in the preparatory 

questions. The purpose of this is to develop problem-solving skills, strengthen conceptual understanding, 

and practice both quantitative and qualitative analysis techniques. 

• Lab activities: an emphasis on constructing and documenting working projects (real instrumentation 

and control systems) to illuminate theoretical knowledge with practical contexts. Special projects 

off-campus or in different areas of campus (e.g. BTC’s Fish Hatchery) are encouraged. Hands-on 

troubleshooting exercises build diagnostic skills. 

• Feedback questions: sets of practice problems at the end of each course section challenge your 

knowledge and problem-solving ability in current as as well as first year (Electronics) subjects. These 

are optional assignments, counting neither for nor against your grade. Their purpose is to provide you 

and your instructor with direct feedback on what you have learned. 

• Tours and guest speakers: quarterly tours of local industry and guest speakers on technical topics 

add breadth and additional context to the learning experience. 

STUDENT ASSIGNMENTS/REQUIREMENTS: All assignments for this course are thoroughly 

documented in the following course worksheets located at: 

http://openbookproject.net/books/socratic/sinst/index.html 

• INST262 sec1.pdf 




4

EVALUATION AND GRADING STANDARDS: (out of 100% for the course grade) 

• Mastery exams and mastery lab objectives = 50% of course grade 

• Proportional exams = 40% (2 exams at 20% each) 

• Lab questions = 10% (2 question sets at 5% each) 

• Quiz penalty = -1% per failed quiz 

• Tardiness penalty = -1% per incident (1 “free” tardy per course) 

• Attendance penalty = -1% per hour (12 hours “sick time” per quarter) 

• Extra credit = +5% per project 

All grades are criterion-referenced (i.e. no grading on a “curve”) 

100% ≥ A ≥ 95% 95% > A- ≥ 90% 

90% > B+ ≥ 86% 86% > B ≥ 83% 83% > B- ≥ 80% 

80% > C+ ≥ 76% 76% > C ≥ 73% 73% > C- ≥ 70% (minimum passing course grade) 

70% > D+ ≥ 66% 66% > D ≥ 63% 63% > D- ≥ 60% 60% > F 

Graded quizzes at the start of each classroom session gauge your independent learning. If absent or 

late, you may receive credit by passing a comparable quiz afterward or by having your preparatory work 

(reading outlines, work done answering questions) thoroughly reviewed prior to the absence. 

Absence on a scheduled exam day will result in a 0% score for the proportional exam unless you provide 

documented evidence of an unavoidable emergency. 

If you fail a mastery exam, you must re-take a different version of that mastery exam on a different 

day. Multiple re-tries are allowed, on a different version of the exam each re-try. There is no penalty levied 

on your course grade for re-taking mastery exams, but failure to successfully pass a mastery exam by the 

due date (i.e. by the date of the next exam in the course sequence) will result in a failing grade (F) for the 

course. 

If any other “mastery” objectives are not completed by their specified deadlines, your overall grade 

for the course will be capped at 70% (C- grade), and you will have one more school day to complete the 

unfinished objectives. Failure to complete those mastery objectives by the end of that extra day (except in 

the case of documented, unavoidable emergencies) will result in a failing grade (F) for the course. 

“Lab questions” are assessed by individual questioning, at any date after the respective lab objective 

(mastery) has been completed by your team. These questions serve to guide your completion of each lab 

exercise and confirm participation of each individual student. Grading is as follows: full credit for thorough, 

correct answers; half credit for partially correct answers; and zero credit for major conceptual errors. All 

lab questions must be answered by the due date of the lab exercise. 

Extra credit opportunities exist for each course, and may be assigned to students upon request. The 

student and the instructor will first review the student’s performance on feedback questions, homework, 

exams, and any other relevant indicators in order to identify areas of conceptual or practical weakness. Then, 

both will work together to select an appropriate extra credit activity focusing on those identified weaknesses, 

for the purpose of strengthening the student’s competence. A due date will be assigned (typically two weeks 

following the request), which must be honored in order for any credit to be earned from the activity. Extra 

credit may be denied at the instructor’s discretion if the student has not invested the necessary preparatory 

effort to perform well (e.g. lack of preparation for daily class sessions, poor attendance, no feedback questions 

submitted, etc.). 

5

REQUIRED STUDENT SUPPLIES AND MATERIALS: 

• Course worksheets available for download in PDF format 

• Lessons in Industrial Instrumentation textbook, available for download in PDF format 

→ Access worksheets and book at: http://openbookproject.net/books/socratic/sinst 

• Spiral-bound notebook for reading annotation, homework documentation, and note-taking. 

• Instrumentation reference CD-ROM (free, from instructor). This disk contains many tutorials and 

datasheets in PDF format to supplement your textbook(s). 

• Tool kit (see detailed list) 

• Simple scientific calculator (non-programmable, non-graphing, no unit conversions, no numeration 

system conversions), TI-30Xa or TI-30XIIS recommended 

ADDITIONAL INSTRUCTIONAL RESOURCES: 

• The BTC Library hosts a substantial collection of textbooks and references on the subject of 

Instrumentation, as well as links in its online catalog to free Instrumentation e-book resources available 

on the Internet. 

• “BTCInstrumentation” channel on YouTube (http://www.youtube.com/BTCInstrumentation), hosts 

a variety of short video tutorials and demonstrations on instrumentation. 

• ISA Student Section at BTC meets regularly to set up industry tours, raise funds for scholarships, 

and serve as a general resource for Instrumentation students. Membership in the ISA is $10 per year, 

payable to the national ISA organization. Membership includes a complementary subscription to InTech 

magazine. 

• ISA website (http://www.isa.org) provides all of its standards in electronic format, many of which 

are freely available to ISA members. 

• Normal Accidents, by Charles Perrow. ISBN-10: 0691004129 ; ISBN-13: 978-0691004129. 

• Instrument Engineer’s Handbook, Volume 2: Process Control and Optimization, edited by Béla Lipták, 

published by CRC Press. 4th edition ISBN-10: 0849310814 ; ISBN-13: 978-0849310812. 

• Purdy’s Instrument Handbook, by Ralph Dewey. ISBN-10: 1-880215-26-8. A pocket-sized field reference 

on basic measurement and control. 

• Cad Standard (CadStd) or similar AutoCAD-like drafting software (useful for sketching loop and 

wiring diagrams). Cad Standard is a simplified clone of AutoCAD, and is freely available at: 

http://www.cadstd.com 

• To receive classroom accommodations, registration with Disability Support Services (DSS) is required. 

Call 360-752-8450, email mgerard@btc.ctc.edu, or visit the DSS office in the Counseling and Career 

Center (room 106, College Services building). 

file INST262syllabus 

6

Summer quarter 

INST 230 -- 3 cr 

Motor Controls 


PLC Programming 


PLC Systems 

Sequence of second-year Instrumentation courses 

Prerequisite for all INST24x, 

INST25x, and INST26x courses 

Graduate!!! 

Fall quarter Winter quarter Spring quarter 


Pressure/Level Measurement 


Temp./Flow Measurement 


Analytical Measurement 

All courses 

completed? No 

Yes 

Core Electronics -- 3 qtrs 

including MATH 141 (Precalculus 1) 

INST 200 -- 1 wk 

Intro. to Instrumentation 

7 


Final Control Elements 


PID Control 


Loop Tuning 

PTEC 107 -- 5 cr 

Process Science 

Prerequisite for INST206 


Job Prep I 


Job Prep II 

(Only if 4th quarter was Summer: INST23x) 

Offered 1 st week of 

Fall, Winter, and 

Spring quarters 


Data Acquisition Systems 

INST 262 -- 5 cr 

DCS and Fieldbus 


Control Strategies 

ENGT 122 -- 6 cr 

CAD 1: Basics 

Offered 1 st week of 

Fall, Winter, and 

Spring quarters

The particular sequence of courses you take during the second year depends on when you complete all 

first-year courses and enter the second year. Since students enter the second year of Instrumentation at four 

different times (beginnings of Summer, Fall, Winter, and Spring quarters), the particular course sequence 

for any student will likely be different from the course sequence of classmates. 

Some second-year courses are only offered in particular quarters with those quarters not having to be 

in sequence, while others are offered three out of the four quarters and must be taken in sequence. The 

following layout shows four typical course sequences for second-year Instrumentation students, depending on 

when they first enter the second year of the program: 







PLC Systems 

Fall quarter 









Winter quarter 


Job Prep I 




PID Control 


Loop Tuning 

Spring quarter 


Job Prep II 







ENGT 122 -- 6 cr 

CAD 1: Basics 

Graduation! 

Possible course schedules depending on date of entry into 2nd year 

Beginning in Summer Beginning in Fall Beginning in Winter Beginning in Spring 

July 

Aug. 

Sept. 

Dec. 

Jan. 

Mar. 

April 

June 

PTEC 107 -- 5 cr 


file sequence 

Sept. 

Dec. 

Jan. 

Mar. 

April 

June 

July 

Aug. 

Fall quarter 











Job Prep I 




PID Control 


Loop Tuning 

PTEC 107 -- 5 cr 




Job Prep II 







ENGT 122 -- 6 cr 

CAD 1: Basics 







PLC Systems 

Graduation! 

8 

Jan. 

Mar. 

April 

June 

July 

Aug. 

Sept. 

Dec. 







PID Control 


Loop Tuning 

PTEC 107 -- 5 cr 




Job Prep I 







ENGT 122 -- 6 cr 

CAD 1: Basics 







PLC Systems 

Fall quarter 


Job Prep II 







Graduation! 

April 

June 

July 

Aug. 

Sept. 

Dec. 

Jan. 

Mar. 










ENGT 122 -- 6 cr 

CAD 1: Basics 







PLC Systems 

Fall quarter 


Job Prep I 









Job Prep II 




PID Control 


Loop Tuning 

PTEC 107 -- 5 cr 


Graduation!

General student expectations 

Your future employer expects you to: show up for work on time, prepared, every day; to work safely, 

efficiently, conscientiously, and with a clear mind; to be self-directed and take initiative; to follow through 

on all commitments; and to take responsibility for all your actions and for the consequences of those actions. 

Instrument technicians work on highly complex, mission-critical measurement and control systems, where 

incompetence and/or lack of integrity invites disaster. This is also why employers check legal records and 

social networking websites for signs of irresponsibility when considering a graduate for hire. Substance abuse 

is particularly noteworthy since it impairs reasoning, and this is first and foremost a “thinking” career. 

(Mastery) You are expected to master the fundamentals of your chosen craft. Accordingly, you will be 

challenged with “mastery” assessments ensuring 100% competence in specific knowledge and skill areas (with 

multiple opportunities to re-try if necessary). Failure to pass any mastery assessment by the deadline results 

in your grade for that course being capped at a C-, with one more day given to demonstrate mastery. Failure 

to pass the mastery assessment during that extra day results in a failing grade for the course. 

(Punctuality and Attendance) You are expected to arrive on time, every scheduled day, and attend all 

day, just as you would for a job. If a session begins at 12:00 noon, 12:00:01 is considered late. Each student 

has 12 “sick hours” per quarter applicable to absences not verifiably employment-related, school-related, 

weather-related, or required by law. Each student must confer with the instructor to apply “sick hours” to 

any missed time – this is not done automatically for the student. Students may donate unused “sick hours” 

to whomever they specifically choose. You must contact your instructor and team members immediately if 

you know you will be late or absent, and it is your responsibility to catch up on all missed activities. Absence 

on an exam day will result in a zero score for that exam, unless due to a documented emergency. 

(Independent study) Industry advisors and successful graduates have consistently identified the ability to 

independently learn new concepts and technologies as the most important skill for this career. You will build 

this vital skill by studying new facts and concepts before class begins, and you will be held accountable every 

day for this preparatory learning and for your problem-solving during class time. It is your responsibility to 

check the course schedule (given on the front page of every worksheet) to identify assignments and due dates. 

Most students find 2 hours per day the absolute minimum time commitment for adequate study. Question 

0 (included in every worksheet) lists practical tips for independent learning and problem-solving. 

(Safety) You are expected to work safely in the lab just as you will be on the job. This includes wearing 

proper attire (safety glasses when working with tools producing chips or dust, no open-toed shoes in the 

lab), implementing lock-out/tag-out procedures when working on circuits over 24 volts, using ladders to 

reach high places rather than standing on tables or chairs, and maintaining an orderly work environment. 

(Teamwork) You will work in instructor-assigned teams to complete lab assignments, just as you will work 

in teams to complete complex assignments on the job. As part of a team, you must keep your teammates 

informed of your whereabouts in the event you must step away from the lab or cannot attend for any 

reason. Any student regularly compromising team performance through absence, tardiness, disrespect, 

unsafe work, or other disruptive behavior(s) will be expelled from their team and required to complete all 

labwork independently for the remainder of the quarter. 

(Responsibility for actions) If you lose or damage college property (e.g. lab equipment), you must find, 

repair, or help replace it. If your actions strain the relationship between the program and an employer (e.g. 

poor behavior during a tour or an internship), you must make amends. The general rule here is this: “If 

you break it, you fix it!” 

(Disciplinary action) The Student Code of Conduct (Washington Administrative Codes WAC 495B- 

120) explicitly authorizes disciplinary action against misconduct including: academic dishonesty (e.g. 

cheating, plagiarism), dangerous or lewd behavior, theft, harassment, intoxication, destruction of property, 

or disruption of the learning environment. 

9

General student expectations (continued) 

Formal learning is a partnership between instructor and student: both are responsible for maximizing 

learning. Your instructors’ responsibilities include – but are not limited to – maintaining an environment 

conducive to learning, providing necessary learning resources, continuously testing your comprehension, 

dispensing appropriate advice, and actively challenging you to think deeper than you would be inclined to 

do on your own (just like an athletic trainer will “push” their clients to go faster, farther, and work harder 

than they would otherwise do on their own). Your responsibilities as a student include – but are not limited 

to – prioritizing time for study, utilizing all learning resources offered to you, heeding your instructor’s advice, 

and above all taking your role as a learner seriously. 

The single most important factor in any student’s education is that student’s dedication. The most 

talented instructor, at the most well-equipped institution, is worthless if the student doesn’t care to learn. 

Conversely, virtually no circumstance can prevent a dedicated student from learning whatever they want. 

In order to clearly illustrate what dedication to learning looks like from a student’s perspective, the 

following clarifications are given: 

You are here to learn, not to receive a high grade, not to earn a degree, and not even to get a job. If you 

make learning your first priority, you will attain all those other goals as a bonus. If, however, you attempt 

to achieve those secondary goals to the exclusion of learning, you will seriously compromise your long-term 

success in this career, and you will have wasted your time here. 

Memorization alone is not learning. Sadly, many students’ educational experiences lead them to believe 

learning is nothing more than an accumulation of facts and procedures, when in truth you will need to do 

much more than memorize new things in order to be successful as an instrument technician. True learning 

is gaining the ability to think in new ways. The “gold standard” of learning is when you have grasped a 

concept so well that you are able to apply it in creative ways to applications and contexts completely new 

to you. In fact, this is a simple way for you to test your own learning: see how well you are able to apply it 

to new scenarios. 

Observation alone is not learning. Merely watching someone else perform a task, execute a procedure, 

or solve a problem does not mean you are proficient in the same, any more than watching an athlete play the 

game means you now can play at the same skill level. Unless and until you can consistently and independently 

apply your knowledge, you haven’t learned. 

The goal of any learning activity is to master the underlying principles, not merely to complete 

the activity. The instructor does not need your answers to homework problems. The instructor does not 

need your completed lab project. What the instructor needs is a demonstration of your competence in 

applying foundational concepts to real applications. The activity itself is nothing more than a means to an 

end – merely a tool for sharpening skills and demonstrating competence. As such, you should never mistake 

the result of the activity (a finished product) for the goal of the activity (conceptual learning). 

The most important question to ask “Why?” Ask yourself this question constantly as you learn new 

things. Why does this new concept work the way it does? Why does this procedure produce results? Why 

are we learning this skill? Why does the instructor keep referring me to the literature instead of just giving 

me the answer I need? “Why” is a catalyst for deeper understanding. 

There are no shortcuts to learning. Relying on classmates for answers rather than figuring them out for 

yourself, skipping learning activities because you think they’re too challenging or take too long, and other 

similar “shortcuts” do nothing to help you learn. Let me be clear on this point: I am not advising you 

to avoid shortcuts in your learning; I’m telling you shortcuts to learning don’t actually exist at all. Any 

time you think you’ve discovered a shortcut to learning, what you have actually done is find a way to avoid 

learning. Learning is hard work – always! Accept this fact and do the hard work necessary to learn. 

file expectations 

10

General tool and supply list 

Wrenches 

• Combination (box- and open-end) wrench set, 1/4” to 3/4” – the most important wrench sizes are 7/16”, 

1/2”, 9/16”, and 5/8”; get these immediately! 

• Adjustable wrench, 6” handle (sometimes called “Crescent” wrench) 

• Hex wrench (“Allen” wrench) set, fractional – 1/16” to 3/8” 

• Optional: Hex wrench (“Allen” wrench) set, metric – 1.5 mm to 10 mm 

• Optional: Miniature combination wrench set, 3/32” to 1/4” (sometimes called an “ignition wrench” set) 

Note: when turning a bolt, nut, or tube fitting with a hexagonal body, the preferred ranking of hand 

tools to use (from first to last) is box-end wrench or socket, open-end wrench, and finally adjustable wrench. 

Pliers should never be used to turn the head of a fitting or fastener unless it is absolutely unavoidable! 

Pliers 

• Needle-nose pliers 

• Tongue-and-groove pliers (sometimes called “Channel-lock” pliers) 

• Diagonal wire cutters (sometimes called “dikes”) 

Screwdrivers 

• Slotted, 1/8” and 1/4” shaft 

• Phillips, #1 and #2 

• Jeweler’s screwdriver set 

• Optional: Magnetic multi-bit screwdriver (e.g. Klein Tools model 70035) 

Measurement tools 

• Tape measure. 12 feet minimum 

• Optional: Vernier calipers 

• Optional: Bubble level 

Electrical 

• Multimeter, Fluke model 87-IV or better 

• Wire strippers/terminal crimpers with a range including 10 AWG to 18 AWG wire 

• Soldering iron, 10 to 25 watt 

• Rosin-core solder 

• Package of compression-style fork terminals (e.g. Thomas & Betts “Sta-Kon” part number 14RB-10F, 

14 to 18 AWG wire size, #10 stud size) 

Safety 

• Safety glasses or goggles (available at BTC bookstore) 

• Earplugs (available at BTC bookstore) 

Miscellaneous 

• Simple scientific calculator (non-programmable, non-graphing, no unit conversions, no numeration 

system conversions), TI-30Xa or TI-30XIIS recommended. Required for some exams! 

• Teflon pipe tape 

• Utility knife 

• Optional: Flashlight 

An inexpensive source of high-quality tools is your local pawn shop. Look for name-brand tools with 

unlimited lifetime guarantees (e.g. Sears “Craftsman” brand, Snap-On, etc.). Some local tool suppliers give 

BTC student discounts as well! 

file tools 

11

Methods of instruction 

This course develops self-instructional and diagnostic skills by placing students in situations where they 

are required to research and think independently. In all portions of the curriculum, the goal is to avoid a 

passive learning environment, favoring instead active engagement of the learner through reading, reflection, 

problem-solving, and experimental activities. The curriculum may be roughly divided into two portions: 

theory and practical. 

Theory 

In the theory portion of each course, students independently research subjects prior to entering the 

classroom for discussion. This means working through all the day’s assigned questions as completely as 

possible. This usually requires a fair amount of technical reading, and may also require setting up and 

running simple experiments. At the start of the classroom session, the instructor will check each student’s 

preparation with a quiz. Students then spend the rest of the classroom time working in groups and directly 

with the instructor to thoroughly answer all questions assigned for that day, articulate problem-solving 

strategies, and to approach the questions from multiple perspectives. To put it simply: fact-gathering 

happens outside of class and is the individual responsibility of each student, so that class time may be 

devoted to the more complex tasks of critical thinking and problem solving where the instructor’s attention 

is best applied. 

Classroom theory sessions usually begin with either a brief Q&A discussion or with a “Virtual 

Troubleshooting” session where the instructor shows one of the day’s diagnostic question diagrams while 

students propose diagnostic tests and the instructor tells those students what the test results would be 

given some imagined (“virtual”) fault scenario, writing the test results on the board where all can see. The 

students then attempt to identify the nature and location of the fault, based on the test results. 

Each student is free to leave the classroom when they have completely worked through all problems and 

have answered a “summary” quiz designed to gauge their learning during the theory session. If a student 

finishes ahead of time, they are free to leave, or may help tutor classmates who need extra help. 

The express goal of this “inverted classroom” teaching methodology is to help each student cultivate 

critical-thinking and problem-solving skills, and to sharpen their abilities as independent learners. While 

this approach may be very new to you, it is more realistic and beneficial to the type of work done in 

instrumentation, where critical thinking, problem-solving, and independent learning are “must-have” skills. 

12

Lab 

In the lab portion of each course, students work in teams to install, configure, document, calibrate, and 

troubleshoot working instrument loop systems. Each lab exercise focuses on a different type of instrument, 

with a eight-day period typically allotted for completion. An ordinary lab session might look like this: 

(1) Start of practical (lab) session: announcements and planning 

(a) The instructor makes general announcements to all students 

(b) The instructor works with team to plan that day’s goals, making sure each team member has a 

clear idea of what they should accomplish 

(2) Teams work on lab unit completion according to recommended schedule: 

(First day) Select and bench-test instrument(s) 

(One day) Connect instrument(s) into a complete loop 

(One day) Each team member drafts their own loop documentation, inspection done as a team (with 

instructor) 

(One or two days) Each team member calibrates/configures the instrument(s) 

(Remaining days, up to last) Each team member troubleshoots the instrument loop 

(3) End of practical (lab) session: debriefing where each team reports on their work to the whole class 

Troubleshooting assessments must meet the following guidelines: 

• Troubleshooting must be performed on a system the student did not build themselves. This forces 

students to rely on another team’s documentation rather than their own memory of how the system was 

built. 

• Each student must individually demonstrate proper troubleshooting technique. 

• Simply finding the fault is not good enough. Each student must consistently demonstrate sound 

reasoning while troubleshooting. 

• If a student fails to properly diagnose the system fault, they must attempt (as many times as necessary) 

with different scenarios until they do, reviewing any mistakes with the instructor after each failed 

attempt. 

file instructional 

13

Distance delivery methods 

Sometimes the demands of life prevent students from attending college 6 hours per day. In such cases, 

there exist alternatives to the normal 8:00 AM to 3:00 PM class/lab schedule, allowing students to complete 

coursework in non-traditional ways, at a “distance” from the college campus proper. 

For such “distance” students, the same worksheets, lab activities, exams, and academic standards still 

apply. Instead of working in small groups and in teams to complete theory and lab sections, though, students 

participating in an alternative fashion must do all the work themselves. Participation via teleconferencing, 

video- or audio-recorded small-group sessions, and such is encouraged and supported. 

There is no recording of hours attended or tardiness for students participating in this manner. The pace 

of the course is likewise determined by the “distance” student. Experience has shown that it is a benefit for 

“distance” students to maintain the same pace as their on-campus classmates whenever possible. 

In lieu of small-group activities and class discussions, comprehension of the theory portion of each course 

will be ensured by completing and submitting detailed answers for all worksheet questions, not just passing 

daily quizzes as is the standard for conventional students. The instructor will discuss any incomplete and/or 

incorrect worksheet answers with the student, and ask that those questions be re-answered by the student 

to correct any misunderstandings before moving on. 

Labwork is perhaps the most difficult portion of the curriculum for a “distance” student to complete, 

since the equipment used in Instrumentation is typically too large and expensive to leave the school lab 

facility. “Distance” students must find a way to complete the required lab activities, either by arranging 

time in the school lab facility and/or completing activities on equivalent equipment outside of school (e.g. 

at their place of employment, if applicable). Labwork completed outside of school must be validated by a 

supervisor and/or documented via photograph or videorecording. 

Conventional students may opt to switch to “distance” mode at any time. This has proven to be a 

benefit to students whose lives are disrupted by catastrophic events. Likewise, “distance” students may 

switch back to conventional mode if and when their schedules permit. Although the existence of alternative 

modes of student participation is a great benefit for students with challenging schedules, it requires a greater 

investment of time and a greater level of self-discipline than the traditional mode where the student attends 

school for 6 hours every day. No student should consider the “distance” mode of learning a way to have 

more free time to themselves, because they will actually spend more time engaged in the coursework than 

if they attend school on a regular schedule. It exists merely for the sake of those who cannot attend during 

regular school hours, as an alternative to course withdrawal. 

file distance 

14

General advice for successful learning 

Focus on principles, not procedures 

• Effective problem-solvers don’t bother trying to memorize procedures for problem-solving because 

procedures are too specific to the type of problem. Rather, they internalize general principles applicable 

to a wide variety of problems. 

• When asking questions about some new subject, concentrate on “why” rather than “how” or “what.” 

Cultivate meta-cognitive skills (the ability to monitor your own thinking on a subject)! 

• Whenever you get “stuck” trying to understand a concept, clearly identify where you are getting stuck, 

and where things stop making sense. 

• When you think you understand a concept, test your understanding by explaining it in your own words. 

You can do this by trying to explain it to a willing classmate, or by imagining yourself trying to explain 

it to someone. If you cannot clearly explain a concept to someone else, you do not understand it well 

enough yourself! 

• The technique of trying to explain a concept also works well to identify where you are stuck. The point 

at which you find yourself unable to clearly articulate the concept is very likely the exact point of your 

misconception or confusion. 

Join or create a study group with like-minded classmates! 

• Read the textbook assignments together. 

• Solve assigned problems together. 

• Collectively identify difficult concepts and areas needing clarification, to bring up later during class. 

• Take turns trying to explain complicated concepts to each other, then critiquing those explanations. 

Eliminate distractions in your life! 

• Time-wasting technologies: televisions, internet, video games, mobile phones, etc. 

• Unhelpful friends, unhealthy relationships, etc. 

Make use of “wasted” time to study! 

• Carefully plan your lab sessions with your teammates to reserve a portion of each day’s lab time for 

study. 

• Bring a meal to school every day and use your one-hour lunch break for study instead of eating out. 

This will not just save you time, but also money! 

• Plan to arrive at school at least a half-hour early (the doors unlock at 7:00 AM) and use the time to 

study as opposed to studying late at night. This also helps guard against tardiness in the event of 

unexpected delays, and ensures you a better parking space! 

Take responsibility for your learning and your life! 

• Do not procrastinate, waiting until the last minute to do something. 

• Obtain all the required books, and any supplementary study materials available to you. If the books 

cost too much, look on the internet for used texts (www.amazon.com, www.half.com, etc.) and use the 

money from the sale of your television and video games to buy them! 

• Make an honest attempt to solve problems before asking someone else to help you. Being able to 

problem-solve is a skill that will improve only if you continue to work at it. 

• If you detect trouble understanding a basic concept, address it immediately. Never ignore an area of 

confusion, believing you will pick up on it later. Later may be too late! 

• Do not wait for others to do things for you. No one is going to make extra effort purely on your behalf. 

. . . And the number one tip for success . . . 

• Realize that there are no shortcuts to learning. Every time you seek a shortcut, you are actually cheating 

yourself out of a learning opportunity!! 

file studytips 

15

Creative Commons License 

This worksheet is licensed under the Creative Commons Attribution License, version 1.0. To view 

a copy of this license, visit http://creativecommons.org/licenses/by/1.0/ or send a letter to Creative 

Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA. The terms and conditions of this 

license allow for free copying, distribution, and/or modification of all licensed works by the general public. 

Simple explanation of Attribution License: 

The licensor (Tony Kuphaldt) permits others to copy, distribute, display, and otherwise use this 

work. In return, licensees must give the original author(s) credit. For the full license text, please visit 

http://creativecommons.org/licenses/by/1.0/ on the internet. 

More detailed explanation of Attribution License: 

Under the terms and conditions of the Creative Commons Attribution License, you may make freely 

use, make copies, and even modify these worksheets (and the individual “source” files comprising them) 

without having to ask me (the author and licensor) for permission. The one thing you must do is properly 

credit my original authorship. Basically, this protects my efforts against plagiarism without hindering the 

end-user as would normally be the case under full copyright protection. This gives educators a great deal 

of freedom in how they might adapt my learning materials to their unique needs, removing all financial and 

legal barriers which would normally hinder if not prevent creative use. 

Nothing in the License prohibits the sale of original or adapted materials by others. You are free to 

copy what I have created, modify them if you please (or not), and then sell them at any price. Once again, 

the only catch is that you must give proper credit to myself as the original author and licensor. Given that 

these worksheets will be continually made available on the internet for free download, though, few people 

will pay for what you are selling unless you have somehow added value. 

Nothing in the License prohibits the application of a more restrictive license (or no license at all) to 

derivative works. This means you can add your own content to that which I have made, and then exercise 

full copyright restriction over the new (derivative) work, choosing not to release your additions under the 

same free and open terms. An example of where you might wish to do this is if you are a teacher who desires 

to add a detailed “answer key” for your own benefit but not to make this answer key available to anyone 

else (e.g. students). 

Note: the text on this page is not a license. It is simply a handy reference for understanding the Legal 

Code (the full license) - it is a human-readable expression of some of its key terms. Think of it as the 

user-friendly interface to the Legal Code beneath. This simple explanation itself has no legal value, and its 

contents do not appear in the actual license. 

file license 

16

• Metric prefixes 

• Yotta = 10 24 Symbol: Y 

• Zeta = 10 21 Symbol: Z 

• Exa = 10 18 Symbol: E 

• Peta = 10 15 Symbol: P 

• Tera = 10 12 Symbol: T 

• Giga = 10 9 Symbol: G 

• Mega = 10 6 Symbol: M 

• Kilo = 10 3 Symbol: k 

• Hecto = 10 2 Symbol: h 

• Deca = 10 1 Symbol: da 

• Deci = 10 −1 Symbol: d 

• Centi = 10 −2 Symbol: c 

• Milli = 10 −3 Symbol: m 

• Micro = 10 −6 Symbol: µ 

• Nano = 10 −9 Symbol: n 

• Pico = 10 −12 Symbol: p 

• Femto = 10 −15 Symbol: f 

• Atto = 10 −18 Symbol: a 

• Zepto = 10 −21 Symbol: z 

• Yocto = 10 −24 Symbol: y 

Metric prefixes and conversion constants 

T G M k 

m µ n p 

tera giga mega kilo (none) milli micro nano pico 

100 103 106 109 1012 10-3 10-6 10-9 10-12 10 2 

• Conversion formulae for temperature 

• o F = ( o C)(9/5) + 32 

• o C = ( o F - 32)(5/9) 

• o R = o F + 459.67 

• K = o C + 273.15 

Conversion equivalencies for distance 

1 inch (in) = 2.540000 centimeter (cm) 

1 foot (ft) = 12 inches (in) 

1 yard (yd) = 3 feet (ft) 

1 mile (mi) = 5280 feet (ft) 

METRIC PREFIX SCALE 

10 1 

10 -1 

10 -2 

hecto deca deci centi 

h da d c 

17

Conversion equivalencies for volume 

1 gallon (gal) = 231.0 cubic inches (in 3 ) = 4 quarts (qt) = 8 pints (pt) = 128 fluid ounces (fl. oz.) 

= 3.7854 liters (l) 

1 milliliter (ml) = 1 cubic centimeter (cm 3 ) 

Conversion equivalencies for velocity 

1 mile per hour (mi/h) = 88 feet per minute (ft/m) = 1.46667 feet per second (ft/s) = 1.60934 

kilometer per hour (km/h) = 0.44704 meter per second (m/s) = 0.868976 knot (knot – international) 

Conversion equivalencies for mass 

1 pound (lbm) = 0.45359 kilogram (kg) = 0.031081 slugs 

Conversion equivalencies for force 

1 pound-force (lbf) = 4.44822 newton (N) 

Conversion equivalencies for area 

1 acre = 43560 square feet (ft 2 ) = 4840 square yards (yd 2 ) = 4046.86 square meters (m 2 ) 

Conversion equivalencies for common pressure units (either all gauge or all absolute) 

1 pound per square inch (PSI) = 2.03602 inches of mercury (in. Hg) = 27.6799 inches of water (in. 

W.C.) = 6.894757 kilo-pascals (kPa) = 0.06894757 bar 

1 bar = 100 kilo-pascals (kPa) = 14.504 pounds per square inch (PSI) 

Conversion equivalencies for absolute pressure units (only) 

1 atmosphere (Atm) = 14.7 pounds per square inch absolute (PSIA) = 101.325 kilo-pascals absolute 

(kPaA) = 1.01325 bar (bar) = 760 millimeters of mercury absolute (mmHgA) = 760 torr (torr) 

Conversion equivalencies for energy or work 

1 british thermal unit (Btu – “International Table”) = 251.996 calories (cal – “International Table”) 

= 1055.06 joules (J) = 1055.06 watt-seconds (W-s) = 0.293071 watt-hour (W-hr) = 1.05506 x 10 10 

ergs (erg) = 778.169 foot-pound-force (ft-lbf) 

Conversion equivalencies for power 

1 horsepower (hp – 550 ft-lbf/s) = 745.7 watts (W) = 2544.43 british thermal units per hour 

(Btu/hr) = 0.0760181 boiler horsepower (hp – boiler) 

Acceleration of gravity (free fall), Earth standard 

9.806650 meters per second per second (m/s 2 ) = 32.1740 feet per second per second (ft/s 2 ) 

18

Physical constants 

Speed of light in a vacuum (c) = 2.9979 × 10 8 meters per second (m/s) = 186,281 miles per second 

(mi/s) 

Avogadro’s number (NA) = 6.022 × 10 23 per mole (mol −1 ) 

Electronic charge (e) = 1.602 × 10 −19 Coulomb (C) 

Boltzmann’s constant (k) = 1.38 × 10 −23 Joules per Kelvin (J/K) 

Stefan-Boltzmann constant (σ) = 5.67 × 10 −8 Watts per square meter-Kelvin 4 (W/m 2 ·K 4 ) 

Molar gas constant (R) = 8.314 Joules per mole-Kelvin (J/mol-K) 

Properties of Water 

Freezing point at sea level = 32 o F = 0 o C 

Boiling point at sea level = 212 o F = 100 o C 

Density of water at 4 o C = 1000 kg/m 3 = 1 g/cm 3 = 1 kg/liter = 62.428 lb/ft 3 = 1.94 slugs/ft 3 

Specific heat of water at 14 o C = 1.00002 calories/g· o C = 1 BTU/lb· o F = 4.1869 Joules/g· o C 

Specific heat of ice ≈ 0.5 calories/g· o C 

Specific heat of steam ≈ 0.48 calories/g· o C 

Absolute viscosity of water at 20 o C = 1.0019 centipoise (cp) = 0.0010019 Pascal-seconds (Pa·s) 

Surface tension of water (in contact with air) at 18 o C = 73.05 dynes/cm 

pH of pure water at 25 o C = 7.0 (pH scale = 0 to 14) 

Properties of Dry Air at sea level 

Density of dry air at 20 o C and 760 torr = 1.204 mg/cm 3 = 1.204 kg/m 3 = 0.075 lb/ft 3 = 0.00235 

slugs/ft 3 

Absolute viscosity of dry air at 20 o C and 760 torr = 0.018 centipoise (cp) = 1.8 × 10 −5 Pascalseconds 

(Pa·s) 

file conversion constants 

19

Question 0 

How to read actively: 

• Avoid shallow annotation methods such as underlining and highlighting. Instead, express your own 

interpretation of the text in a notebook or in the margins of the text. A suggestion is one sentence of 

your own thoughts per paragraph in the text. Expressing your own thoughts as you read is a far more 

effective way to digest the information than simply emphasizing portions of the text! If you do wish to 

emphasize some portion of the text that either makes perfect sense to you or causes confusion, write 

that portion verbatim and include a page number reference in your notes so you may reference it during 

class. 

• Identify as clearly as possible which concepts or points confuse you the most. This is the first and 

most important step to overcoming confusion. The more specific you are, the better your instructor and 

classmates will be able to help you overcome the confusion! 

• If the text demonstrates a mathematical calculation, such as how to apply a new equation to solving a 

problem, pick up your calculator and work through the example as you read! Applications of math are 

an ideal opportunity to actively read a technical book. 

• Maintain a notebook where you express your understanding of general principles applicable to the 

subject(s) you are studying, including mathematical formulae (a formula is really just a precise 

expression of a principle) with brief definitions of terms. 

• Imagine trying to explain what you’ve just read to an intelligent child – someone with the capacity to 

understand but without the experience to immediately relate. This forces you to distill each concept to 

its essence. Your first attempt will rarely be right, but subsequent attempts will get better and better. 

Once you have an explanation that satisfies you, write it out using the fewest words possible. 

Problem-solving tips: 

• Always begin by identifying which general principles you’ve learned apply to the problem, then identify 

how the goal of the problem (i.e. what it is you’re asked to solve) and the “given” information fits with 

those principles. 

• Sketch a diagram to organize all “given” information and show where the answer will fit. 

• Perform “thought experiments” to visualize the effects of different conditions. 

• Work “backward” from a hypothetical solution to a new set of given conditions. 

• Change the problem to make it simpler, and then solve the simplified problem (e.g. change quantitative 

to qualitative, or visa-versa; substitute different numerical values to make them easier to work with; 

eliminate confusing details; add details to eliminate unknowns; consider limiting cases that are easier 

to grasp; put the problem into a more familiar context, or analogy). 

• Specifically identify which portion(s) of the question you find most confusing and need help with. The 

more specifically you are able to express your point(s) of confusion, the better. 

Above all, cultivate persistence in your studies. Persistent effort is necessary for mastery of anything 

non-trivial. The keys to persistence are (1) having the desire to achieve that mastery, and (2) knowing that 

challenges are normal and not an indication of something gone wrong. A common error is to equate easy 

with effective: students often believe learning should be easy if everything is done right. The truth is that 

mastery never comes easy, and that “easier” methods usually substitute memorization for understanding! 

file question0 

20

Question 1 

Questions 

The following screenshot shows the configuration window for an analog input on a Delta DSC-1280 

DDC building automation controller: 

Based on the parameters you see in this configuration window, how many bits does the analog-digital 

converter inside the DDC controller use? 

file i00484 

21

Question 2 

An example of a SCADA component in an electric power system is the General Electric model PQM II 

power quality monitor. This panel-mounted instrument inputs voltage and current signals from the power 

lines through instrument transformers (voltage and current step-down transformers), computing power factor, 

true power (P), reactive power (Q), apparent power (S), frequency, and imbalances of voltage or current 

between the different phases. This device also has the ability to record and trend power system values over 

time. A diagram showing the connections between a PQM II and the power lines is shown here: 

... A 

Three-phase power lines 

(three "hot" conductors and one "neutral") 200:5 

... 

... B 

200:5 

... 

... C 

200:5 

... 

... N 

50:5 

... 

CTs 

PTs 

To ... 

SCADA... 

MTU 

60:1 

60:1 

60:1 

V N 5A Com 5A Com 5A Com 5A Com 

V 3 

V 2 

V 1 

Com 

Voltage inputs 

RS-485 

Phase A Phase B Phase C Neutral 

Current inputs 

GE Multilin PQM II 

Explain why instrument transformers (PTs and CTs with voltage step-down and current step-down 

ratios) are used to connect the PQM to the power system conductors. 

Assuming a phase-to-neutral voltage on “B” phase of 7155 volts AC, calculate the voltage seen between 

the PQM instrument’s V2 and VN terminals. 

Assuming a current of 148 amps AC through the “C” phase conductor of the power lines, calculate the 

current seen at the PQM instrument’s Phase C “5A” terminal. 

Suppose you wished to connect a personal computer with a 9-pin serial port to the 9-pin serial port 

of the PQM. Which terminals of each 9-pin serial port would you need to connect together, at minimum, 

to enable communication between the PQM and the PC? Note: a personal computer is considered a DTE 

device, while the PQM is considered a DCE device! 

Suggestions for Socratic discussion 

• An important safety consideration when working with current transformers (CTs) is to never opencircuit 

the secondary winding of a CT. Explain why. 

22 

9-pin 

RS-232

• For those who have studied three-phase power circuits, calculate the line voltage of this system based 

on the 7155 VAC phase voltage presented above. 

file i02030 

Question 3 

Read selected portions of the National Transportation Safety Board’s safety study, Supervisory Control 

and Data Acquisition (SCADA) in Liquid Pipelines (Document NTSB/SS-05/02 ; PB2005-917005), and 

answer the following questions: 

Question #22 of the Safety Study in Appendix E lists the major features provided by pipeline SCADA 

systems. Identify some of the most popular features. Question #38 lists the number of data points handled 

by each respondent’s SCADA system. Just how data-rich are some of these systems? 

Question #42 of the Safety Study in Appendix E lists the various communication media used by SCADA 

systems to relay data between RTU and MTU points. Explain what each of these terms refers to. How many 

SCADA systems do not use redundant (backup) communication channels between RTU and MTU locations 

(hint: see question #43)? 

Questions #19 and #21 of the Safety Study in Appendix E list the rationale given by respondents as to 

why they are considering an upgrade (or are currently implementing an upgrade) for their SCADA system. 

What are some of the reasons given? Do any of them surprise you? 

The “SCADA Screens and Graphics” section of chapter 4 showcases several examples of graphic displays 

in use in liquid pipeline control systems. How much blank space should there be on any one screen in order 

to avoid “clutter”? How should color schemes be chosen to maximize effectiveness? 

The Safety Study results shown in Appendix E list a number of different manufacturers (“vendors”) 

for SCADA systems used in pipeline control (see question #15). Based on the vendor names and number 

of installations, what is your impression of pipeline SCADA systems in the United States: is there much 

standardization, or is there a wide diversity of system types in use? Is there a clear leader among the 

manufacturers represented in the survey? 

file i00277 

23

Question 4 

Many modern distributed control systems (DCS) also host software to allow communication with HARTenabled 

instruments. One example of such software is Emerson’s AMS: 

What does this particular screenshot reveal about the HART-enabled instruments connected to this 

Emerson DeltaV DCS? What advantages do you think might be realized by having the DCS be able to 

digitally communicate with field instruments? What disadvantages can you see to this method of HART 

interface, as opposed to a hand-held HART communicator? 

24


• With the DCS enabled to “talk” HART with field instruments, one cannot also use a handheld HART 

communicator to “talk” with the same field instruments. Explain why. 

file i00665 

Question 5 

Read and outline the “Introduction to Pseudocode” subsection of the “Digital PID Algorithms” section 

of the “Closed-Loop Control” chapter in your Lessons In Industrial Instrumentation textbook. Note the page 

numbers where important illustrations, photographs, equations, tables, and other relevant details are found. 

Prepare to thoughtfully discuss with your instructor and classmates the concepts and examples explored in 

this reading. 

Feel free to skip past the portions of this subsection discussing branching and functions. 

file i02920 

25

Question 6 

Examine this page of program code from a Siemens APOGEE system (written in Siemens’ “PPCL” 

programming language), then answer the following questions: 

02530 C 

02540 C IF THE ROOM TEMP IS LESS THAN HEATING SETPOINT THAN TURN ON THE HEATING PUMP 

02550 C ELSE SHUT OFF HEATING PUMP 

02560 C 

02570 IF ("MV.GH.2E:ROOM TEMP" .LT. "MV.GH.2E.HTG.STPT") THEN ON ("MV.GH.2E:DO 2") 

02580 IF ("MV.GH.2E:ROOM TEMP" .GT. "MV.GH.2E.HTG.STPT"+1) THEN OFF ("MV.GH.2E:DO 2") 

02590 C 

02600 C *****ROOM 3E CONTROLS***** 

02610 C 

02620 C IF SOMEONE PUSHES THE OVERIDE BUTTON, THEN TURN ON THE EXHAUST FAN 

02630 C OVERRIDE FOR 2 HOURS 

02640 C 

02650 IF ("MV.GH.3E:DI OVRD SW" .EQ. ON) THEN SET (0,"MV.GH.3E.OT") 

02660 IF ("MV.GH.3E.OT" .GT. 1000) THEN SET (1000, "MV.GH.3E.OT") 

02670 IF ("MV.GH.3E.OT" .LT. 120) THEN ON ("MV.GH.3E.OVRD") ELSE OFF ("MV.GH.3E.OVRD") 

What is the significance of the letter C preceding many of the lines of code in this program? 

Identify the meanings of the following “operators” in Siemens PPCL code: .LT., .GT., .EQ.. 

Explain how the “heating pump” code functions (lines 2570 and 2580) to turn the pump on and off. 

Explain how the “exhaust fan override” code functions (lines 2650 and 2670) to turn the fan on for two 

hours. Specifically, where does the code tell the Siemens controller to invoke a two-hour time delay? 

Line 6000 of this program (not shown on this page) instructs the controller to GOTO 00190, with 00190 

being a line near the beginning of the program (also not shown on this page). In fact, this is the only 

“GOTO” instruction in the entire program. Why do you think this “GOTO” instruction exists? 


• Do you think it would be easier or more difficult to program custom control algorithms in a text-based 

language like PPCL or in a graphic-based language such as function blocks? 

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26

Question 7 

Examine this page of program code from a Siemens APOGEE system (written in Siemens’ “PPCL” 

programming language), then answer the following questions: 

04600 C *****SWAMP COOLER CONTROL***** 

04610 C 

04620 C IF ANY WEST ROOM IS GREATER THAN 2 DEG ABOVE ITS SETPOINT, THEN TURN ON 

04630 C THE SWAMP COOLER, ELSE SHUT OFF SWAMP COOLER 

04640 C 

04650 IF ("MV.GH.1W:ROOM TEMP" .GT. "MV.GH.1W.CLG.STPT" + 2) THEN ON ("MV.GH.1W.CLG") 

04652 IF ("MV.GH.1W:ROOM TEMP" .LE. "MV.GH.1W.CLG.STPT") THEN OFF ("MV.GH.1W.CLG") 





04680 C 

04690 IF ("MV.GH.1W.CLG".OR."MV.GH.2W.CLG".OR."MV.GH.3W.CLG") THEN ON ("MV.GH.3W:DO 6") 

ELSE OFF ("MV.GH.3W:DO 6") 

What is the significance of the letter C preceding many of the lines of code in this program, particularly 

the signficance of lines 04610, 04640, and 04680? 

Identify the meanings of the following “operators” in Siemens PPCL code: .LE. and .GT. 

Explain how lines 04650 through 04690 control the “swamp cooler”. 


• Do you think it would be easier or more difficult to program custom control algorithms in a text-based 

language like PPCL or in a graphic-based language such as function blocks? 

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27

Question 8 

A DDC (Direct Digital Control) system used for building automation sends a 4-20 mA control signal to 

a steam valve with an electronic positioner. This particular loop has a problem, for the valve remains in the 

full-closed (0%) position regardless of what the DDC tries to tell it to do. A technician begins diagnosing 

the problem by taking a DC voltage measurement at terminal block TB-11 in this loop circuit: 

TB-10 

cable 30 

TB-11 

. . . 

To other field devices 

. . . 

. . . 

V A 

V 

A 

OFF 

cable 41 

COM 

V 

A 

cable 26 

cable 16 

cable 19 

cable 24 

Analog 

output 

Analog 

output 

DDC system 

Analog 

input 

Analog 

input 

Air supply 

Processor 

The technician knows a reading of 22.6 volts indicates an “open” fault. Based on the location of the 

measured voltage (22.6 VDC), determine where in the wiring a single “open” fault could be located. 

For the next diagnostic test, the technician momentarily connects a jumper wire between the screws of 

TB-10 while continuing to measure voltage at TB-11. The new voltage measurement at TB-11 (with the 

jumper installed) reads 0.0 volts. Determine what this result tells us about the nature and location of the 

fault. 

Explain whether or not there is any danger of introducing a short-circuit into a system like this. Could 

a fuse be blown by doing this test? 


• Explain why it is critically important to determine the identities of the valve and DDC card as being 

either electrical sources or electrical loads when interpreting the diagnostic voltage measurements. 

• Identify some of the pros and cons of this style of testing (measuring voltage at a set of points before 

and after a purposeful wiring short) compared to other forms of multimeter testing when looking for 

either an “open” wiring fault. 

file i00717 

28

Question 9 

Identify the effects of the faults listed (considered one at a time) in this temperature control system: 

Loop Diagram: Reactor 15-A temperature control Revised by: I.M. Hott Date: Feb 30, 1999 

Condensate 

Reactor 

15-A 

Product out 

Field process area 

TE 

37 

Feed in 

Red 

Red 

Wht 

Wht 

A 

B 

C 

D 

Steam 

TV-37 

TY 

37 

TT 

37 

Field 

panel 

2 

3 

P5 

Field 

panel P30 

TB27 

Cbl 20 

TB40 

Tag number Description Manufacturer Model Calibration Notes 

TE-37 

TT-37 

TIC-37 

TY-37 

TV-37 

ATO 

Cbl TV-37 

TB12 

Cbl 1 

Red 

Blk 

Cbl TT-37 

Red 

Blk 

10 

11 

Cbl 3 

20 

21 

3 

4 

22 5 

4-wire platinum RTD Chromalox 100 Ω , α = 0.00392 

Red 

Blk 

Red 

Blk 

Cbl 21 

6 

7 

8 

DCS cabinet 

Red 

Blk 

Red 

Blk 

7 

8 

9 

FTA-AO 

Redundant AI/AO 

TIC 

37 

FTA-AI 

+24 VDC 

Smart temp. transmitter Rosemount 100-250 o F , 4-20 mA Direct action 

DCS controller 

Red 

Blk 

Red 

Blk 

1 

2 

Node 9 

Module 31 

Slot 1 

Node 9 

Module 32 

Slot 4 

I/P transducer Fisher 546 4-20 mA , 3-15 PSI Direct action 

Steam control valve Fisher 

• FTA-AI module resistor fails shorted 

• FTA-AI module resistor fails open 

• Ground wire falls off terminal TB40-8 

• Condensate valve left closed 

• Corroded wire connection at TB12-3 

• Cable 1 fails open 

• Cable 1 fails shorted 

• Cable 21 fails open 

• Cable 21 fails shorted 


4 

12 

23 

24 

25 

Honeywell PM 

Reverse action 

Easy-E 3-15 PSI 

Air-to-open 

• For those who have studied RTD temperature sensors, determine the effect of a short-circuit between 

terminals B and C on temperature transmitter 

file i04019 

29

Question 10 

“Wet” natural gas is mostly methane (CH4) mixed with significant amounts of heavier hydrocarbon 

species such as ethane (C2H6), propane (C3H8), butane (C4H10), and pentane (C5H12). A process for 

separating these heavier hydrocarbons from the chief component (methane) using compression and cooling 

is shown here: 

"Wet" natural gas 

(78% CH4) Filter 

M 

Compressor 

Cryogenic coolant loop 

PSV 

"Dry" natural gas 

(93% CH4) PIC 

115 

PG 

PT 

115 

Flash 

vessel 

LG 

LT 

108 

FIR 

110 

LIC 

108 

Liquid hydrocarbons 

Chilled gases enter the flash vessel, where methane rises and escapes in gaseous form, while all the other 

(heavier) hydrocarbon molecules condense into liquid and exit out the bottom. 

Suppose PT-115 is mis-calibrated, such that it falsely indicates a pressure lower than what is actually 

inside the flash vessel. How will this mis-calibration affect the control of flash vessel pressure? Will the 

operator be able to know anything is wrong by observing the DCS monitor screens for this process? 


• Explain the purpose of the heat exchangers in this P&ID, especially the two exchanging heat between 

the incoming (compressed) gas and the products coming off the top and bottom of the flash vessel. 

• Identify and explain the purpose of the “PSV” valve in this diagram. 

file i03084 

30 

FT 

110

Question 11 

Digital single-loop process controllers are stand-alone units: they require no auxiliary hardware to 

perform their function. As such, they are equipped with analog-to-digital converters (ADC) and digital-toanalog 

converters (DAC) to interface directly with instruments via the traditional 4-20 mA standard. Many 

single-loop controllers also have discrete (on/off) inputs and outputs for interfacing with process switches 

and alarm circuits. Shown here is a typical example of a single-loop controller, front and back: 

Front view Back view 

SP 

100 

0 

Out 

PV 

Displ 

Auto 

Man 

Config 

0 100 

L1 

N 

Gnd 

Aout_1 Dout_1 

Com 

Aout_2 Dout_3 

Ain_1 

Com 

Ain_2 

Din_1 

Din_2 

Din_3 

Com 

Dout_2 

Com 

Distributed control systems (DCS) are quite different. These systems are designed to control hundreds 

or even thousands of loops. As such, they are made in a modular fashion so the users can add whatever 

types of input and output (I/O) capability they need. 

Identify the purpose of each type of I/O module listed here, as it might be applied in a DCS. What 

I’m looking for here is an educated guess from you, as it may be quite a challenge to actually research these 

specific I/O types for different distributed control systems: 

• AI 1-5 VDC 

• AI 4-20 mADC 

• AI 4-20 mADC w/ HART 

• AO 4-20 mA 

• AO w/ HART 

• DI 24VDC dry contact 

• DI 24VDC isolated 

• DI 120VAC isolated 

• DO 24VDC high side 

file i02426 

31

Question 12 

Question 13 

Question 14 

Question 15 

Question 16 

Question 17 

Question 18 

Question 19 

Question 20 

Question 21 

Read and outline the “Zero and Span Adjustments (Analog Instruments)” section of the “Instrument 

Calibration” chapter in your Lessons In Industrial Instrumentation textbook. Note the page numbers where 

important illustrations, photographs, equations, tables, and other relevant details are found. Prepare to 

thoughtfully discuss with your instructor and classmates the concepts and examples explored in this reading. 

file i03903 

Question 22 

Read and outline the “Typical Calibration Errors” section of the “Instrument Calibration” chapter in 

your Lessons In Industrial Instrumentation textbook. Note the page numbers where important illustrations, 

photographs, equations, tables, and other relevant details are found. Prepare to thoughtfully discuss with 

your instructor and classmates the concepts and examples explored in this reading. 

file i03908 

Question 23 

Read and outline the “Damping Adjustments” section of the “Instrument Calibration” chapter in your 

Lessons In Industrial Instrumentation textbook. Note the page numbers where important illustrations, 



file i03904 

Question 24 

Read and outline the “LRV and URV Settings, Digital Trim (Digital Transmitters)” section of the 

“Instrument Calibration” chapter in your Lessons In Industrial Instrumentation textbook. Note the page 

numbers where important illustrations, photographs, equations, tables, and other relevant details are found. 

Prepare to thoughtfully discuss with your instructor and classmates the concepts and examples explored in 

this reading. 

file i03905 

32

Question 25 

Read the “An Analogy for Calibration versus Ranging” section of the “Instrument Calibration” 

chapter in your Lessons In Industrial Instrumentation textbook. Note the page numbers where important 

illustrations, photographs, equations, tables, and other relevant details are found. Prepare to thoughtfully 

discuss with your instructor and classmates the concepts and examples explored in this reading. 

file i03907 

Question 26 

Read and outline the “Calibration Procedures” section of the “Instrument Calibration” chapter in your 




file i03906 

33

Question 27 

In this exercise, you will calibrate an analog RTD transmitter: a field instrument designed to sense the 

electrical resistance of an RTD (Resistive Temperature Detector) and output a corresponding 4-20 mA DC 

signal. To do this exercise, you will need a small flat-bladed screwdriver, some 9-volt batteries, a precision 

digital multimeter, alligator-clip style jumper wires, and some resistors and potentiometers (necessary to 

form a resistor network adjustable within a range of approximately 80 Ω to 150 Ω). Your instructor will 

provide the RTD transmitter and batteries, while students provide all the other tools and components (from 

their first-year lab supplies). It is advised that each and every student bring their multimeter, as multiple 

meters are useful in this exercise: 

Resistor 

network 

simulating 

an RTD 

R 

Z S 

RTD transmitter 

Milliammeter 

9 VDC 

9 VDC 

Your transmitter has a zero adjustment potentiometer as well as a span adjustment potentiometer 

allowing you to make calibration adjustments. Normally, you would use an RTD sensor to provide the input 

resistance to this transmitter, but for the purpose of a classroom exercise we will simulate the resistance of 

an RTD using a resistor network. Your task will be to calibrate the transmitter so that it registers 4 mA at 

the lower range value (LRV) and 20 mA at the upper range value (URV) provided by the instructor. 

Your first step should be determining how to connect the potentiometer to the transmitter to simulate an 

RTD (a variable resistance). Note that simply connecting the three terminals of the potentiometer to the three 

input terminals on the transmitter is incorrect! Pay close attention to the symbols drawn on the transmitter 

near the input terminals – they show you how you must connect an RTD (and therefore your variable test 

resistance) to the transmitter. You must have your instructor verify your intended wire connections before 

powering the transmitter, in order to ensure the circuit will work properly and that the transmitter will not 

be damaged during the procedure. 

Instructor checks wiring plan before power-up: 

Next, your instructor will provide you with reasonable LRV and URV values for your calibration. Use 

the formula shown below to calculate equivalent resistance values for these temperatures: 

• LRV (0% of range) = degrees C = Ω 

• URV (100% of range) = degrees C = Ω 

R = 100[1 + 0.00385T] 

34

Next, build a resistor network using at least one potentiometer to simulate any resistance value within 

these limits (inclusive). You will be using your digital multimeter to measure the network’s resistance as 

you set it to the desired value, then connecting the network to the RTD transmitter to simulate the desired 

temperature while using your multimeter to measure the output current. In this way, you will be able to 

simulate a variety of measured temperatures to the input of the RTD transmitter, while noting how the 

transmitter responds to those simulated conditions. 

Before you make any adjustments to the transmitter’s zero or span screws, you need to simulate five 

points along the temperature range, recording the transmitter’s output in an As-Found calibration table. 

Calculate the error as a percentage of span (e.g. if the transmitter outputs 3.95 mA when it should output 

4.00 mA, the error is -0.3125%): 

Input Resistance Output Output Error 

(%) (Ω) (Ideal) (As-Found) (%) 

0 4 mA 

25 8 mA 

50 12 mA 

75 16 mA 

100 20 mA 

After recording the As-Found values, you will move the zero and span adjustments on the RTD 

transmitter as necessary to bring the transmitter’s calibration in line with the instructor’s specified range. 

You may find that your potentiometer provides too coarse of an adjustment to settle at precisely the 

resistance values you wish during calibration. This will be especially true if the potentiometer’s full-scale 

value is large compared to the desired resistance (e.g. a 1 kΩ potentiometer being used to simulate an RTD 

resistance of 123.7 Ω results in you trying to use a very small range of the potentiometer). One way to 

narrow the resistance range of your potentiometer is to connect it in parallel with a fixed resistor like this: 

1 kΩ R fixed 

R adjustable = 0 to 155 Ω 

What must the size of R fixed be in order 

to provide the desired range of 0 to 155 Ω ? 

For practice, calculate the fixed resistor value necessary to limit this 1 kΩ potentiometer’s adjustment 

range to 0-155 Ω. 

Rfixed = Ω 

Of course, finding a potentiometer with a full-scale range close to the desired resistance adjustment range 

is the best way to go. The parallel fixed-resistor solution is merely a way to “make do” with a potentiometer 

that is less than ideal. 

35

After calibration, you will simulate the same five points along the temperature range specified by the 

instructor, recording the transmitter’s output in an As-Left calibration table along with the calculated errors: 

Input Resistance Output Output Error 

(%) (Ω) (Ideal) (As-Left) (%) 

0 4 mA 

25 8 mA 

50 12 mA 

75 16 mA 

100 20 mA 

Feel free to use a computer spreadsheet to tabulate and graph the As-Found and As-Left results. 


• Did your transmitter initially exhibit a zero error, a span error, and/or a linearity error? 

• In general terms, how is a zero error revealed in a table of As-Found values? 

• In general terms, how is a span error revealed in a table of As-Found values? 

• In general terms, how is a linearity error revealed in a table of As-Found values? 

• In general terms, how is a hysteresis error revealed in a table of As-Found values? 

• Why is it important for an instrument technician to record both As-Found and As-Left results for an 

instrument being calibrated? 

file i02031 

Question 28 

An electronic level transmitter has a calibrated range of 0 to 2 feet, and its output signal range is 4 to 

20 mA. Complete the following table of values for this transmitter, assuming perfect calibration (zero error). 

Be sure to show your work! 

file i00032 

Measured level Percent of span Output signal 

(feet) (%) (mA) 

1.6 

7.1 

40 

36

Question 29 

An important part of performing instrument calibration is determining the extent of an instrument’s 

error. Error is usually measured in percent of span. Calculate the percent of span error for each of the 

following examples, and be sure to note the sign of the error (positive or negative): 

• Pressure gauge 

• LRV = 0 PSI 

• URV = 100 PSI 

• Test pressure = 65 PSI 

• Instrument indication = 67 PSI 

• Error = % of span 

• Weigh scale 

• LRV = 0 pounds 

• URV = 40,000 pounds 

• Test weight = 10,000 pounds 

• Instrument indication = 9,995 pounds 


• Thermometer 

• LRV = -40 o F 

• URV = 250 o F 

• Test temperature = 70 o F 

• Instrument indication = 68 o F 


• pH analyzer 

• LRV = 4 pH 

• URV = 10 pH 

• Test buffer solution = 7.04 pH 

• Instrument indication = 7.13 pH 


Also, show the math you used to calculate each of the error percentages. 

Challenge: build a computer spreadsheet that calculates error in percent of span, given the LRV, URV, 

test value, and actual indicated value for each instrument. 

file i00089 

Question 30 

A common form of measurement error in instruments is called hysteresis. A very similar type of 

measurement error is called deadband. Describe what these errors are, and differentiate between the two. 

file i00091 

37

Question 31 

An instrument technician working for a pharmaceutical processing company is given the task of 

calibrating a temperature recording device used to display and log the temperature of a critical batch 

vessel used to grow cultures of bacteria. After removing the instrument from the vessel and bringing it to a 

workbench in the calibration lab, the technician connects it to a calibration standard which has the ability 

to simulate a wide range of temperatures. This way, she will be able to test how the device responds to 

different temperatures and make adjustments if necessary. 

Before making any adjustments, though, the technician first inputs the full range of temperatures to this 

instrument to see how it responds in its present condition. Then, the instrument indications are recorded 

as As-Found data. Only after this step is taken does the technician make corrections to the instrument’s 

calibration. Then, the instrument is put through one more full-range test and the indications recorded as 

As-Left data. 

Explain why it is important that the technician make note of both “As-Found” and “As-Left” data? 

Why not just immediately make adjustments as soon as an error is detected? Why record any of this data 

at all? Try to think of a practical scenario where this might matter. 

file i00082 

Question 32 

Question 33 

Question 34 

Question 35 

Question 36 

Question 37 

Question 38 

Question 39 

Question 40 

Question 41 

Read and outline the “Instrument Turndown” section of the “Instrument Calibration” chapter in your 




file i03909 

Question 42 

Read and outline the “NIST Traceability” section of the “Instrument Calibration” chapter in your 




file i03910 

38

Question 43 

Identify the types of instrument calibration errors shown in these graphs: 

Output Ideal 

file i01036 

Input 

Actual 

Output 

Ideal 

Actual 

39 

Input 

Output Ideal 

Input 

Actual

Question 44 

A “smart” (digital) DP pressure transmitter is removed from service and taken to a calibration bench 

for testing. A technician connects a precision pressure gauge and air source to the transmitter’s high port 

while monitoring the 4-20 mA output signal using a DMM: 

Precision 

pressure 

regulator 

Compressed 

air supply 

H L 

(vent) 

PSI 

Digital pressure gauge 

Loop resistor 

DMM 

+ − 24 VDC 

V 

HART communicator 

Online 

1 Device setup 

2 PV 28.75 PSI 

3 AO 17.14 mA 

4 LRV 0.00 PSI 

5 URV 35.00 PSI 

V A 

Calculate the amount of sensor trim error as well as the amount of output trim error, both expressed in 

percent of span. Also, explain why the HART communicator is necessary to be able to separately calculate 

these error values. 


• What other possible sources of error besides the transmitter could account for these discrepancies? 

• Suppose another instrument technician suggests to you that a problem within the precision air pressure 

regulator might account for some (or all!) of the calibration error seen in the data, and that we should 

replace the regulator with another. How would you respond to this suggestion? 

file i02033 

40 

A 

OFF 

COM 

mA 

A

Question 45 

Read Fluke’s Transmitter Calibration with the Fluke 750 Series Documenting Process Calibrator 

application note (document 3792201B A-EN-N, August 2011) and answer the following questions: 

Identify the four different instrument calibration examples in this application note. Are any of these 

similar to an instrument calibration you have done? 

Explain the advantage of using the “Auto Test” feature of the Fluke DPC to perform an instrument 

calibration, compared to performing a manual calibration test. 

Explain why the fourth calibration example in this application note cannot be done using the “Auto 

Test” capability of the Fluke DPC. 

When manually providing the input values for this instrument under test, is it necessary for you to 

exactly settle at each test point? Explain why or why not. 

file i01940 

Question 46 

Read Fluke’s Calibrating Pressure Switches with a DPC application note (document 2069058B A-EN-N, 

July 2011) and answer the following questions: 

Define “deadband” as used in this document with reference to a pressure switch, and explain why this 

is an important parameter for a process switch. 

Explain why it is important to tell the DPC whether the setpoint type is “low” or “high”. 

Explain why a pressure switch calibration check cannot be done using the “Auto Test” capability of the 

Fluke DPC, but rather must be done using the “Manual Test” feature. 

file i01941 

41

Question 47 

The Fluke corporation sells a software product called DPCTrack2 that may be downloaded and run for 

a free trial basis. Locate this software on the Fluke website (http://www.fluke.com) and download it to 

your PC so that you may experiment with it in class. 

DPCTrack2 is used to upload calibration specifications to a process calibrator (e.g. the Fluke model 754) 

prior to instrument technicians performing a field or a bench calibration. After the calibration(s) have been 

completed, the calibrator is re-connected to the personal computer so the As-Found and As-Left calibration 

results may be downloaded to DPCTrack2 for archival. Thus, DPCTrack2 is useful for calibration workload 

management: ensuring all technicians have the information necessary to properly complete mission-critical 

field instrument calibrations, and ensuring all the calibration data gets properly archived. 

In this exercise, you will enter data for a few instruments as they appear on the following P&ID. Choose 

any instruments you wish from the P&ID (choosing a few within the same control loop would be best, because 

that would allow you to define a “Loop” in the DPCTrack software as well as the instruments themselves), 

giving yourself license to invent realistic calibration ranges for each of them: 

From 50 PSI 

steam header 

Dwg. 13301 

From nitrogen 

header 

Dwg. 13322 

From acid gas 

separator 

Dwg. 25311 

PG 

315 

ST 

FT 

29 

V-10 

SOUR WATER TANK 

8’-0" Dia 12’-0" Sidewall 

DP Atmosphere 

DT 190 

FI 

37 

o F 

P-201 

2" thick 

insul 

PG 

316 

LP cooling water 

Dwg. 31995 ST 

ST 

ST 

V-10 

P-201 

SOUR WATER TANK EDUCTOR 

85 ACFM @ 1" H2O 

Set @ 

2" vac. 

2" press. 

HLL 

From sour water 

flash drum 

PG 

ST 

Dwg. 25309 299 

ST 

TG 

20 

LT 

18 

FI 

29 

LIR 

18 

LI 

18 

LSH 

18 

LSH 

18 

FIR 

29 

LG 

19 

LAH 

18 

LAL 

18 

LLL 

1’-0" 

10’-6" 

TG 

346 

PAL 

201 

PSL 

201 

PSV 

355 

PAH 

202 

24" MH 

Strainer 

PSH 

202 

PG 

459 

FI 

97 

P-101 

P-101 

COOLING WATER PUMP 

20 GPM @ 80 o F 

Rated head: 80 PSI 

PG 

402 

ST 

Set @ 

100 PSI 

PSV 

354 

FI 

98 

pH 

AIT 

348 

TG 

345 

PG 

300 

AIR 

348 L 

PG 

461 

FQ 

27 

P-102 

SOUR WATER PUMP 

5 GPM @ 80 o F 


ST 

Set @ 

60 PSI 

P-102 

FIC 

H 

27 

L 

FT 

27 

FIC 

28 

FT 

28 

PCV 

10 

E-2 

ST 

Set @ 

75 PSI 

I 

/P 

FY 

27 

FV 

27 

FIR 

28 L 

FV 

28 

PG 

405 

Slope 

NC 

I /P 

FY 

28 

NC 

PSLL 

204 

PSV 

352 

42 

P-103 

STRIPPED WATER PUMP 

8 GPM @ 150 o F 


ST 

PG 

441 

ST 

TG 

343 

Set @ 

50 PSI 

PSV 

353 

2" thick 

insul 

PG 

463 

NC 

LLL 

1’-3" 

P-103 

NLL 

C-7 

Liquid dist. 

10’ packed bed 

10’ packed bed 

Steam dist. 

2’-6" 

ST 

HLL 

4’-1" 

C-7 

SOUR WATER STRIPPER 

12" x 40’ SS 

DP 55 PSIG 

DT 350 o F 

Each bed 10’ of 1" pall rings 

TT 

TIC 

21 21 

TG 

344 

1 1/2" 

TI 

340 

PG 

401 

1 1/2" 

ST 

TIR 

21 

Mag 

ST 

ST 

ST 

LAL 

11 

LSL 

LSLL 11 

203 

I 

LG 

11 

TV 

21 

NC 

1" 

1" 

PG 

422 

3/4" 

3/4" 

E-2 

SOUR WATER HEATER 

Rated duty: 300 MBTU/HR 

Shell design: 70 PSI @ 360 o F 

Tube design: 125 PSI @ 360 o F 

Slope 

PG 

406 

1/2" 

1" 

1" 

pH 

AIT AIR 

347 347 

LT 

12 

LY 

12 

P /I 

LIR LR 

12a 12b 

L 

Slope 

TG 

26 

Cond 

AIT 

342 

AAH 

342 

M 

FT 

30 

FIR 

30 

M 

FT 

31 

PC 

115 

PV 

115 

LAH LAL 

12 12 

LSH LSL 

12 12 

H 

L 

LIC 

12 

Set @ 

100 PSI 

PSV 

351 

FIR 

31 L 

E-9 

STRIPPED WATER COOLER 

Rated duty: 50 MBTU/HR 

Shell design: 150 PSI @ 350 o F 

Tube design: 150 PSI @ 350 o F 

ST 

PG 

438 

TG 

477 

E-9 

ST 

LV 

12 

ST 

Cond 

AIT AAH 

341 341 

TG 

480 

PG 

312 

TG 

478 TG 

479 

NC 

ST 

To flare header 

Dwg. 13320 

To incinerator 

Dwg. 13319 

LP cooling water 

Dwg. 31995 

To water treatment 

Dwg. 45772

Your assignment – at minimum – is to enter multiple instruments into the DPCTrack2 database, 

complete with one or more “Test Point Groups” specifying calibration parameters for those instruments. 

An example of this is shown here: 

Beyond that, feel free to experiment with entering more data into the DPCTrack2 database: 

• Equipment data (assigning individual instruments to a piece of equipment) 

• Loop data (assigning individual instruments to a loop) 

• Location data (assigning equipment to certain buildings or other physical locations) 

• Technician information 

• User’s manuals or other instructional documents linked to loops or instruments 

file i02034 

Question 48 

Question 49 

Question 50 

Question 51 

Question 52 

43

Question 53 

Question 54 

Question 55 

Question 56 

Question 57 

Question 58 

Question 59 

Question 60 

44

Question 61 

Suppose an electronic pressure transmitter has an input range of 0 to 100 PSI and an output range of 

4 to 20 mA. When subjected to a 5-step up-and-down “As-Found” calibration test, it responds as such: 

Applied pressure Output signal 

(PSI) (mA) 

0 3.5 

25 7.5 

50 11.5 

75 15.5 

100 19.5 

Sketch this instrument’s ideal transfer function on the graph below, along with its actual transfer function 

graph based on the measured values recorded above. Then, determine what kind of calibration error it has 

(zero shift, span shift, and/or linearity): 

Output 

(mA) 

20 

16 

12 

8 

4 

0 

0 

Input 

(PSI) 

Finally, identify how this calibration error might be corrected. What steps or procedures would you 

follow to rectify this problem? 


25 

• How might the other two calibration errors appear when graphed? 

• Which constant in the y = mx + b linear equation represents zero, and which represents span? 

• Describe how a computer spreadsheet program (e.g. Microsoft Excel) might be a useful tool in graphing 

this instrument’s response. 

file i00081 

45 

50 

75 

100

Question 62 

An electronic DP transmitter has an input range of 0 to 100 inches water column and an output range 

of 4 to 20 mA. When subjected to a series of known pressures, it responds as such: 


(” WC) (mA) 

0 4.0 

25 8.7 

50 12.8 

75 16.6 

100 20.0 

Graph this instrument’s ideal transfer function on the graph below, along with its actual transfer function 

graph based on the measured values recorded above. Then, determine what kind of calibration error it has 

(zero shift, span shift, and/or linearity). 

Output 

(mA) 

20 

16 

12 

8 

4 

0 

0 

25 

50 

Input 

("W.C.) 

Hint: a computer spreadsheet program might be a useful tool in graphing this instrument’s response. 

Feel free to attach a printed copy of a spreadsheet graph instead of hand-sketching one on this page. 

file i03859 

46 

75 

100

Question 63 

In this process, two chemical streams are mixed together in a reactor vessel. The ensuing chemical 

reaction is endothermic (heat-absorbing) and must be heated by steam to ensure the solution is at the 

necessary temperature to thoroughly react. A temperature transmitter (TT) senses the reaction product 

temperature and sends a 4-20 mA signal to a temperature indicating controller (TIC). The controller then 

sends a 4-20 mA control signal to the temperature valve (TV) to throttle steam flow: 

P 

Steam in 

ATO 

Feed A Feed B 

TV 

TT 

TIC 

Reactor 

TI 

Condensed water out 

Reaction product out 

Suppose the last instrument technician to calibrate the temperature transmitter made a mistake, and 

the transmitter consistently reads 15 o too hot. For example, if the reaction product temperature is actually 

275 o F, the transmitter outputs a current signal corresponding to 290 o F. 

Describe in detail the effect this mis-calibration will have on the performance of the heating system. 


• Would this calibration error be apparent on the faceplate of the controller (i.e. an offset of 15 o F between 

PV and SP)? Why or why not? 

file i04386 

47

Question 64 

This room pressure control system maintains a slightly positive pressure in a precision electronic 

assembly room to prevent dust from entering from the outside, while always ensuring a rapid flow rate 

of air through the room. It regulates pressure by modulating two variable-speed fans: one introducing air to 

the room (the “forced draft” fan) and one venting air from the room (the “induced draft” fan). A pressure 

transmitter outputs 4 mA at 0 ”W.C room pressure and 20 mA at 2 ”W.C. room pressure: 

ID fan 

Air out 

Door 

SP = +0.5" WC 

PIC 

PT 

(set at 25%) 

HC 

Assembly room 

Filter 

VFD VFD 

Air in 

FD fan 

PDT 

PDIR 

Suppose you are called to troubleshoot a problem in this system: the room air pressure is holding steady 

at +1.03 inches WC (according to the display on the DDC control system). Based on this data, identify the 

most likely cause of the problem, and also how you would confirm your diagnosis before making any repairs. 


• What does “VFD” stand for, and what exactly do the “VFD” boxes do to exert control over the speed 

of the two fan motors? 

• Explain why VFD control of air flow into and out of a forced-ventilation building makes more sense 

than using valve, dampers, or louvers to do the same. 

file i00403 

48

Question 65 

This single-loop control system has a problem: the pressure indicated on the controller’s faceplate shows 

it to be precisely at setpoint (95 inches W.C.), yet the pressure gauge does not agree. 

V 4 

Pressure 

transmitter 

V 1 

FC 

Gauge reads 

46 "W.C. 

H L 

0 to 100 "WC 

250 Ω 

V 2 V 3 

TB1 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

I/P transducer 

(170 Ω coil resistance) 

A.S. 

Air from blower 

Single-loop controller 

Input 

Output 

H N G 

24 VDC 

H 

N 

G 

E.S. 

Black 

White 

Green 

Power supply 

Determine the diagnostic value of each of the following tests. Assume only one fault in the system, 

including any single component or any single wire/cable/tube connecting components together. If a proposed 

test could provide new information to help you identify the location and/or nature of the one fault, mark 

“yes.” Otherwise, if a proposed test would not reveal anything relevant to identifying the fault (already 

discernible from the measurements and symptoms given so far), mark “no.” 

file i00583 

Diagnostic test Yes No 

Measure AC line voltage 

Measure DC power supply output voltage 

Inspect PID tuning parameters in controller 

Check pressure transmitter calibration 

Measure transmitter current signal 

Put controller into manual mode and move valve 

Measure DC voltage between TB1-3 and TB1-4 


49

Question 66 

An operator claims pressure gauge PG-108 is defective and needs to be replaced. This pressure gauge 

registers 50 PSI, while pressure controller PIC-33 and pressure recorder PR-33 both register the pressure 

as being equal to setpoint: 43 PSI. Before replacing this pressure gauge, however, you decide to do some 

diagnostic thinking to see if there might be other causes for the abnormally high reading at PG-108. The 

first thing you check is the position of control valve PV-33a, and you find its stem position to be at 35% 

open. 

600 PSI steam 

Dwg. 10957 

Bottoms product 

Dwg. 28544 

Fractionator feed 

from charge heater 

Dwg. 27004 

PG 

122 

1000 PSI steam 

Dwg. 10957 

E-5, E-6, E-7 

FEED HEAT RECOVERY EXCHANGERS 

80 MM BTU/hr 

Shell 500 PSIG @ 650 o F 

Tube 660 PSIG @ 730 o F 

FT 

41 

PG 

106 

AIC 

42 

AIT 

42 

PG 

PG 

123 124 

RO 

NOTES: 

1. Backup (steam-driven) pumps automatically started by 2oo2 trip 

logic, where both pressure switches must detect a low-pressure 

condition in order to start the backup pump. 

IAS 

PG 

107 

M 

FC 

NC 

P 

FY 

40c 

FOUNDATION Fieldbus FFC 

41 

Set @ 

410 PSI 

PSL 

60 

PSL 

61 

FOUNDATION Fieldbus 

FV 

41 

I 

PG 

125 

TIR TT 

50 50 

TIR TT 

51 51 

TIR TT 

52 52 

TIR TT 

59 59 

Note 1 

E-8 

E-9 

OVERHEAD PRODUCT CONDENSER 

BOTTOMS REBOILER 

Tube 165 PSIG @ 400 o Shell 120 PSIG @ 650 

F 

o 55 MM BTU/hr 70 MM BTU/hr 

F 

Shell 630 PSIG @ 800 o F 

Tube 600 PSIG @ 880 o F 

2. Transit-time ultrasonic flowmeter with pressure and temperature 

compensation for measuring overhead gas flow to flare line. 

RO 

P-10 P-11 

PG 

121 

PG 

136 

PG 

130 

S S 

R IAS 

FO 

E-5 

E-6 

E-7 

Lead/Lag 

Lead/Lag 

FY 

FY 

40a 40b 

FT 

40 

TT TIR 

53 53 

TT TIR 

54 54 

TT TIR 

55 55 

TT TIR 

56 56 

PG 

138 

LAH 

58 

LAL 

57 

PG 

127 

LSH 

58 

LG 

39 

LSL 

57 

P-10 P-11 P-12 P-13 P-14 

P-15 

OVERHEAD MAIN CHARGE FEED PUMP BACKUP CHARGE FEED PUMP 

MAIN BOTTOMS PRODUCT PUMP BACKUP BOTTOMS PRODUCT PUMP 

MAIN OVERHEAD PRODUCT PUMP BACKUP PRODUCT PUMP 

2100 GPM @ 460 PSID 1900 GPM @ 460 PSID 2880 GPM @ 70 PSID 2880 GPM @ 70 PSID 2350 GPM @ 55 PSID 2350 GPM @ 55 PSID 

Set @ 52 PSI Set @ 52 PSI 

Set @ 55 PSI 

HLL = 7’-2" 

NLL = 5’-4" 

LLL = 3’-8" 

C-5 

Set @ 55 PSI 

IAS 

FOUNDATION Fieldbus FC 

FOUNDATION Fieldbus FT 

31 

31 

FV 

P 31 

FO 

NC 

AIC 

36 

AT 

36 

PG 

131 

LT 

38a 

Radar 

LT 

38b 

PG 

120 

FT 

35 

FT 

37 

Magnetostrictive (float) 

LT 

38c 

PG 

119 

RO 

Note 2 

FT 

68 PT 

68 

FIC FY 

35 

35 

PSL 

62 

PSL 

63 

M 

PG 

132 

Median 

select 

LY 

H 

LIC FIC 

38 

38 L 37 

I 

Note 1 

PG 

112 

TT 

68 

FY 

68 

NC 

RO 

IAS 

FV 

35 

PG 

113 

Modbus RS-485 FIQ 

68 

IAS 

S S 

R 

FO 

E-9 

FO 

NC 

P 

FV 

37 


PG 

137 

PG 

115 

PG 

108 

PG 

116 

RO 

PT 

33 

PSL 

64 

PSL 

65 

M 

PG 

111 

H PIC 

33 L 

I 

PG 

117 

V-13 

C-5 

MAIN FRACTIONATION TOWER 

Dia 10’-3" Height 93’ 

DP 57 PSIG 

DT 650 o F top, 710 o F bottom 

PG 

PG 

HC 

140 

HC 

141 

HC 

142 143 144 

Set @ 

Set @ 

PG 

500 PSI 

IAS 

100 PSI 

139 

RTD 

IAS 

PY 

33b 

PG 

109 

E-8 

P-12 P-13 P-14 P-15 

PG 

114 

PAH 

66 

PSH 

66 

PG 

133 

PR 

33 

PY 

33a 

Note 1 

PG 

134 

Set @ 

73 PSI 

PG 

118 

RO 

FT 

34 

S S 

FO 

NC 

R 

PV 

33a 

9 to 15 PSI 

H LIC 


30 L 

IAS 

LG LT 

32 30 

FO 

NC 

FO 


IAS 

PV 

33b 

3 to 9 PSI 

FIR 

67 

FT 

67 

M 


FC 

NC 

FC 

FY 

34 34 

P 

V-13 

OVERHEAD ACCUMULATOR 

DP 81 PSIG 

DT 650 o F 

Identify the likelihood of each specified fault in this process. Consider each fault one at a time (i.e. no 

multiple faults), determining whether or not each fault could independently account for all measurements 

and symptoms in this process. 

Fault Possible Impossible 

PG-108 calibration error 

PT-33 calibration error 

PIC-33 left in manual mode 

PY-33a calibration error 

PY-33b calibration error 

Finally, identify the next diagnostic test or measurement you would make on this system. Explain how 

the result(s) of this next test or measurement help further identify the location and/or nature of the fault. 

50 

PG 

110 

FV 

34 

PG 

135 

RTD 

FT 

TT 

69 PT 69 

69 

FY 

69 

To LP flare 

Dwg. 62314 

Cooling water 

return 

Dwg. 11324 

HP cooling water 

Dwg. 11324 

Overhead product 

Dwg. 28542 

FIR 

69 

Distillate product 

Dwg. 28543 

Sidedraw product 

Dwg. 28545 

Condensate return 

Dwg. 10957 

Condensate return 

Dwg. 10957


• Based on the information you have at this point, can you tell whether any suspected calibration error 

is due to a mis-adjustment of zero or of span? Explain why or why not. 

• Is controller PIC-33 direct-acting or reverse-acting? How can you tell? 

• Does control valve PV-33a throttle gas or liquid? How can you tell? 

• Identify a typographical error in this P&ID. 

file i03512 

51

Question 67 

This boiler steam drum level control system has a problem. The water level in the steam drum is below 

setpoint (as indicated by the controller display showing 42% water level with a 50% setpoint), and has been 

for the past several hours despite the operator’s attempt to raise water level by raising the setpoint on the 

controller. Meanwhile, the boiler is operating at full power, making steam at a normal rate of flow: 

A.S. 

TB-17 

Feedwater 

SP 

LIC 

PV 

LY 

I /P 

TB-25 

Burner 

LT 

Exhaust stack 

Riser 

tubes 

Steam drum 

water 

Downcomer 

tubes 

Mud drum 

Identify the likelihood of each specified fault for this system. Consider each fault one at a time (i.e. no 


and symptoms in this system. 


LT calibration error 

LY calibration error 

Controller failed 

Low air supply pressure 

Excessive resistance in LT circuit 

Excessive resistance in LY circuit 

Feedwater pump worn 

Controller in manual mode 

Finally, identify the next diagnostic test or measurement you would make on this system. Bear in mind 

that this is an operating system and cannot be shut down to accommodate any arbitrary test. Explain how 


file i01368 

52 

Steam

Question 68 

Large electric power distribution transformers are filled with a special high-dielectric oil that helps 

transfer heat from the transformer core to cooling tubes, as well as displace moisture from the internal 

volume of the device. One of the important operational parameters of such transformers is the temperature 

of this oil. 

A special-purpose protection device called a thermal overload protective relay (ANSI/IEEE code number 

49) uses an RTD sensor to detect the transformer’s temperature, then energizes the circuit breaker’s “trip” 

coil (causing the breaker to open its contacts) if ever this temperature exceeds a certain pre-set value. A 

basic schematic diagram shows how this relay device triggers the circuit breaker to trip if necessary to protect 

the transformer against over-temperature: 

From 

115 kVAC 

3-phase 

source 

Circuit breaker 

TC 

Trip coil 

125 VDC 

station battery 

Fuse Fuse 

Three-phase power transformer 

Trip contacts 

115 kV 

primary 

RTD temperature sensing 

49 protective relay 

RTD RTD 

Control power in 

Gnd 

13.8 kV 

secondary 

To 

13.8 kVAC 

3-phase 

load(s) 

Identify how you would perform an “As-Found” test on this protective relay to ensure it would act 

to trip the circuit breaker in the event the transformer got too hot, without actually tripping the breaker. 

In other words, devise a “live” test of the protective relay that does not actually interrupt power to the 

transformer during the test. Assume the transformer’s trip temperature setting is 60 degrees Celsius, and 

that the formula relating RTD resistance with temperature is as follows: 

R = 100[1 + 0.00385T] 

Be sure to specify any temporary changes you would make to the wiring in order to safely conduct your 

“As-Found” test, and describe the step-by-step procedure as though you were giving instuctions to another 

technician to perform the test instead of you. 


• The specific sequence in which you perform the steps of your As-Found calibration test is every bit 

as important as the steps themselves! Identify where an improper sequence of otherwise proper steps 

would cause things to go wrong during the test. 

53

• For those who have studied RTD sensors before, identify the proper amount of resistance equivalent to 

60 degrees Celsius from an RTD table rather than using the given formula. 

file i02032 

54

Question 69 

This control system measures and regulates the amount of differential pressure across a gas compressor, 

by opening a recirculation valve to let high-pressure discharge gas go back to the low-pressure “suction” of 

the compressor. This control system needs to be very fast-acting, and currently it is anything but that, as 

revealed by the open-loop trend shown in the upper-right of this illustration: 

Gas out 

terminal block 

35 PSI 

instrument air 

PDIC 

PV SP 

PDY 

(I/P) 

PDY 

(volume 

booster) 

H L 

PDT 

PDV 

Discharge Suction 

Compressor 

PDT 

PDV 

Open-loop test 

Gas in 

1 second 

Electric 

motor 

Identify what type of problem you think you are dealing with here, as the compressor’s differential 

pressure should not take several seconds to stabilize following a sudden move by the recirculation valve. Also 

suggest a next diagnostic test or measurement to take, explaining how the result(s) of that test help further 

identify the location and/or nature of the fault. 


• Based on the evidence presented, how do you know this problem is definitely not caused by poor PID 

controller tuning? 

• What other methods exist for controlling differential pressure across a large gas compressor, other than 

using a recirculation valve? 

file i00586 

55

Question 70 

Gas flow control processes differ somewhat from liquid flow control processes, the former tending to be 

more difficult to control than the latter. Consider the following process, controlling the flow of gas out of a 

pressure-controlled vessel: 

Gas in 

Gas in 

Gas in 

Gas in 

PIC 

PT 

FT 

Gas out 

FIC 

Gas out 

When the flow indicating controller (FIC) is placed in manual mode and the output “bumped” 10%, 

the result is certainly not what you would expect to see in a liquid flow control system: 

% 

100 

95 

90 

85 

80 

75 

70 

65 

60 

55 

50 

45 

40 

35 

30 

25 

20 

15 

10 

5 

0 

0:00 

Output 

PV 

0:30 1:00 1:30 2:00 2:30 

Time (Minutes : Seconds) 

Explain the odd shape of the process variable (PV) trend following the output step-change: why the 

flow increases, then “sags,” then stabilizes. Identify a diagnostic test you could perform on this process to 

positively identify the source of this strange behavior, explaining how the result(s) of this next test would 

help you identify the cause. 

file i03400 

56

Question 71 

Question 72 

Question 73 

Question 74 

Question 75 

Question 76 

Question 77 

Question 78 

Question 79 

Question 80 

Question 81 

Suppose you need to trigger an alarm light to come on if ever a process measurement signal (4-20 

mA) exceeds an operator-determined trip point. The 4-20 mA loop-powered transmitter has already been 

installed, and wired to a spare analog input (#4) on a Siemens model 353 loop controller. The alarm light 

has also been wired to an unused digital (discrete) output on the same controller (#1). 

Sketch a simple function-block program to perform this alarm function based on the library of function 

blocks available in the Siemens model 353 controller. 

file i04268 

57

Question 82 

Oil refineries and other heavy industries dealing with large quantities of flammable gases often use flares 

as emergency devices to safely burn off gas vented from one or more process units. This P&ID of a typical 

flare gas system shows how liquids are “knocked out” of the flammable gas headed to the flare, and how 

flames are prevented from following back from the flare tip to the flare line by means of a water seal: 

LP flare gas 

header 

Dwg. 10143 

Process water 

Dwg. 13241 

30 PSI steam 

Dwg. 13249 

ST 

OWS 

PG 

36 

LV 

24 

PG 

35 

Knockout drum 

NC 

FO 

LG 

25 

ST 

LSH 

19 

LAH 

19 

LT 

24 

LG 

20 

LC 

24 

WirelessHART 

LIR H 

24 

LY 

24 

L 

LV 

21 

ST 

ST 

LC 

21 

FC 

NC 

LT 

21 

TT RTD 

27 

TIR 

27 

WirelessHART 

L 

PG 

36 

Water seal 

drum 

OWS 

T 

Steam 

trap 

TT 

26 

TC 

26 

ST 

LSH 

22 

LSL 

23 

NC 

FO 

Flare tip 

TV 

26 

LP condensate 

Describe the practical purpose of each controller in this P&ID (i.e. explain the reason why we have 

a controller installed and working in each case), and then determine its proper action. Assuming all 

transmitters are direct-acting (greater measured variable = greater signal output), determine the proper 

action (direct or reverse) for each controller in this system. 

• Knockout drum LC-24 = direct or reverse? The purpose of this controller is to . . . 

• Water seal drum LC-21 = direct or reverse? The purpose of this controller is to . . . 

• Water seal drum TC-26 = direct or reverse? The purpose of this controller is to . . . 

file i04694 

58 

LAH LAL 

22 23 

Dwg. 13249

Question 83 

This pressure-control system does not appear to be regulating water pressure correctly. The SP is set 

for 110 PSI (out of a 0-150 PSI range), but the PV display on the controller faceplate registers only 27 PSI, 

and has for quite a while. You happen to notice that the controller output reads 38% on the faceplate: 

Controller 

PV SP 

Out 

Air-to-open 

valve 

Water out 

(back to sump) 

Water in 

(from pump) 

Transducer 

Air supply 

I/P 

Pressure gauge 

Filter 

L 

PT 

H 

0 to 150 PSI 

Pressure 

transmitter 

Water out 

(to points of use) 

Your first test is to measure loop current in the circuit connecting the pressure transmitter to the pressure 

controller. There, your multimeter registers 6.88 milliamps. Your next step is to record the pressure gauge’s 

indication (at the I/P output tube): 7.5 PSI. 

Identify the likelihood of each specified fault for this control system. Consider each fault one at a 

time (i.e. no multiple faults), determining whether or not each fault could independently account for all 

measurements and symptoms in this circuit. 


PT out of calibration (outputting wrong current) 

PIC input out of calibration (not interpreting PV signal properly) 

PIC output out of calibration (not sending correct mA signal to I/P) 

Pressure gauge out of calibration (not displaying pressure properly) 

I/P out of calibration (not outputting correct pressure) 

Control valve is oversized 

Control valve is undersized 

PIC is poorly tuned (not making good control “decisions”) 

Instrument air supply not at full pressure 

file i00338 

59

Question 84 

In preparation to disconnect and remove an electric motor for rebuild, an electrician shuts off the circuit 

breaker feeding the motor control circuit, then places a lock and an informational tag on that breaker so 

that no one turns it back on before she is done with the job. 

The next step is to confirm the absence of dangerous voltage on the motor conductors before physically 

touching any of them. This confirmation, of course, is done with a voltmeter, and we all know that voltage 

is measured between two points. The question now is, how many different combinations of points must the 

electrician measure between using her voltmeter to ensure there is no hazardous voltage present? 

Conduit 

V A 

V 

A 

OFF 

COM 

A 

T1 T2 T3 

List all possible pairs of points the electrician must check for voltage between. Don’t forget to include 

earth ground as one of those points, in addition to T1, T2, and T3! 

Next, write a mathematical formula to calculate the number of point-pair combinations (i.e. the number 

of different voltage measurements that must be taken) given N number of connection points in the circuit. 

file i04259 

60

Question 85 

Suppose a voltmeter registers 0 volts between test points C and E in this series-parallel circuit: 

16 volts 

(0.25 amp 

current-limited) 

A 

B 

+ − 

1 kΩ 

C 

D 

R 2 

R 3 

1 kΩ 

R 1 

1 kΩ 

Identify the likelihood of each specified fault for this circuit. Consider each fault one at a time (i.e. no 


and symptoms in this circuit. 


R1 failed open 



R1 failed shorted 



Voltage source dead 

Finally, identify the next diagnostic test or measurement you would make on this system. Explain how 


file i04484 

61 

E 

F

Question 86 

A V-notch weir is a type of flow-sensing element for measuring liquid flow through open channels. Its 

construction is similar to a dam, and the height of liquid (“head”) on its upstream side is related to flow 

rate over the weir by a nonlinear equation. 

Suppose the height signal from a level transmitter upstream of a 60 o V-notch weir gets sent to the 

analog input of a process recorder. Displaying the height measurement directly on the recorder would not be 

very useful, because height (H) is not linearly proportional to flow rate (Q). A human operator looking at a 

trend of head could not tell what this trend means in terms of flow, or worse yet might mistakenly interpret 

the head trend as a flow trend. However, this recorder does have the feature of characterization, where you 

may enter an equation to “linearize” an otherwise non-linear signal. 

Write a “linearization” formula so that the trend recorder will be able to input the measured height (H, 

in inches) upstream of a 60 o V-notch weir and display as a flow rate (Q) in units of cubic feet per second. 

file i04347 

62

Question 87 

A digital pressure transmitter has a calibrated input range of 50 to 200 PSI, and a 10-bit output (0 to 

1023 “count” range). Complete the following table of values for this transmitter, assuming perfect calibration 

(zero error): 

file i03826 

Input pressure Percent of span Counts Counts 

(PSI) (%) (decimal) (hexadecimal) 

7 

22 

39 

56 

78 

63

Question 88 

Suppose an electronic pressure transmitter has an input range of 0 to 400 PSI and an output range of 

4 to 20 mA. When subjected to a series of known pressures to obtain an “As-Found” calibration table, it 

responds as such: 


(PSI) (mA) 

0 4.0 

100 8.0 

200 12.0 

300 16.0 

400 20.0 

300 16.1 

200 12.1 

100 8.1 

0 4.1 

Identify the type of calibration error this transmitter suffers from. 

file i01205 

64

Question 89 

Shown here is a pair of loop-powered 4-20 mA process transmitters, a process controller with dual 

measurement inputs, and a 4-20 mA I/P (current-to-pressure) converter used to drive a pneumaticallyactuated 

control valve. The controller inputs are ranged from 1 to 5 volts DC, not 4-20 mA: 

4-20 mA looppowered 

transmitter Process controller 

4-20 mA looppowered 

transmitter 

4-20 mA I/P converter 

Control valve 

+24 VDC 

X 

Y 

Gnd 

Out 

Gnd 

+ − 

ADC 

ADC 

Output 

4-20 

mA 

Show how all three field devices would properly connect to the controller, including the placement 

of resistors to convert the current signals into voltage signals that the controller’s ADC’s may interpret. 

Furthermore, use shielded cable, showing where all shield ground connections should be located. 

file i02273 

65

Question 90 

The following strobe light has a problem: the flash tube never flashes. 

6 V 

On/off 

R 1 

R 2 

C 1 

TP1 

Q 1 

TP3 

R 3 

R 4 

Q 2 

TP2 

C 2 

R 5 

Q 3 

T 1 

Flash tube 

Turning the flash rate control (rheostat R1) to the slowest position, you take two voltage measurements 

with a voltmeter: at test point 3 (between TP3 and ground) you measure a voltage rhythmically pulsating 

between about 1.5 and 4 volts DC. At test point 6 (between TP6 and ground) you measure about 0.3 volts 

DC all the time. 

From this information, identify two possible faults (either one of which could account for the problem 

and all measured values in this circuit), and also identify two circuit elements that could not possibly be to 

blame (i.e. two things that you know must be functioning properly, no matter what else may be faulted) 

other than the 6 volt battery and the on/off switch. The circuit elements you identify as either possibly 

faulted or properly functioning can be wires, traces, and connections as well as components. Be as specific 

as you can in your answers, identifying both the circuit element and the type of fault. 

• Circuit elements that are possibly faulted 

1. 

2. 

• Circuit elements that must be functioning properly 

1. 

2. 

file i03187 

66 

TP4 

TP5 

TP6 

R 6 

Q 4

Question 91 

Lab Exercise 

Your task is to build, document, and successfully operate a process controlled by a recording PID 

controller. Several alternative process types exist and are documented in subsequent pages. The working 

process you build will be used in future lab exercises this quarter to meet other learning objectives, which 

means you will not disassemble this project at the completion of these lab objectives as you normally would. 

The following table of objectives show what you and your team must complete within the scheduled 

time for this lab exercise. Note how some of these objectives are individual, while others are for the team as 

a whole: 

Objective completion table: 

Performance objective Grading 1 2 3 4 Team 

Choose process to build mastery – – – – 

Prototype sketch (before building the system!) mastery – – – – 

Final loop diagram and system inspection mastery – – – – 

Process and Instrument Diagram (P&ID) mastery – – – – 

Trend graph displays PV and Output mastery – – – – 

Process exhibits good control behavior mastery – – – – 

PV alarm(s) defined and enabled mastery – – – – 

Lab question: Selection/testing proportional – – – – 

Lab question: Commissioning proportional – – – – 

Lab question: Mental math proportional – – – – 

Lab question: Diagnostics proportional – – – – 

The only “proportional” scoring in this activity are the lab questions, which are answered by each 

student individually in a private session between the instructor and the team. A listing of potential lab 

questions are shown at the end of this worksheet question. The lab questions are intended to guide your 

labwork as much as they are intended to measure your comprehension, and as such the instructor may ask 

these questions of your team day by day, rather than all at once (on a single day). 

It is essential that your team plans ahead what to accomplish each day. A short (10 

minute) team meeting at the beginning of each lab session is a good way to do this, reviewing 

what’s already been done, what’s left to do, and what assessments you should be ready for. 

There is a lot of work involved with building, documenting, and troubleshooting these working 

instrument systems! 

As you and your team work on this system, you will invariably encounter problems. You should always 

attempt to solve these problems as a team before requesting instructor assistance. If you still require 

instructor assistance, write your team’s color on the lab whiteboard with a brief description of what you 

need help on. The instructor will meet with each team in order they appear on the whiteboard to address 

these problems. 

CALIBRATED 

By: Date: 

Range: 

Cut out tag(s) with scissors, then affix to instrument(s) using transparent tape to show calibration: 

CALIBRATED 

By: Date: 

Range: 

67 

CALIBRATED 

By: Date: 

Range: 

CALIBRATED 

By: Date: 

Range:

Lab Exercise – choosing a process to build 

There are a number of process types to choose from when selecting the one you will build with your 

team. The only non-negotiable limitations is that the process must be safe, legal, and possible to complete 

in the time allotted for this lab. What follows are some examples: 

Air pressure control 

From compressed 

air supply (30 PSI) 

Alternatively, let the supply air be 

manually controlled and the pressure 

controller modulate the vent valve. 

Air turbine speed control 

From compressed 

air supply (30 PSI) 

"Muffin" fans (like those used for 

cooling personal computers) work 

surprisingly well as turbines and 

tachogenerators! 

A smart temperature transmitter 

configured for millivolt signal input 

works well as a speed transmitter, 

combined with a voltage divider to 

reduce the tach’s output signal 

down to a millivolt range. 

PY 

I /P 

Pressure 

vessel 

Tach Turbine 

ST 

68 

Vent 

PRC 

SY 

PT 

I /P 

Vent 

SRC

Water level control 

Fountain-style water pumps work well for 

this purpose, so long as the total pumping 

height (head) is not too great. 

Alternatively, let the in-flow be manually 

controlled and the level controller modulate 

the drain valve. 

Pump 

Water flow control 

Fountain-style water pumps work well for 

this purpose, so long as the total pumping 

height (head) is not too great. 

Simple venturi tubes may be fabricated 

using bell reducers and straight pipe sections, 

in either plastic or metal. 

Alternatively, let the venturi flow be manually 

controlled and the flow controller modulate 

the bypass valve. 

Pump 

69 

Bypass 

LY 

LRC 

FT 

Bypass 

I /P 

FRC 

FY 

LT 

I /P

Oven temperature control 

A cheap electric toaster oven or convection oven 

works well for this purpose. The only "hard-tofind" 

part is the power controller (JC) which 

modulates AC power to the heating element 

in accordance with the temperature controller’s 

4-20 mA output signal. 

Solar air heater control 

For the purposes of this lab exercise, the solar 

collector may be made out of cardboard with 

clear plastic food wrap as the cover material. 

Paint the inside of the collector flat black for 

maximum heat absorption capability. 

Use a variable-frequency motor drive (VFD) 

if the fan is turned by an AC motor. If using 

a DC fan (e.g. computer cooling fan), you may 

use a simpler PWM power controller. 

Other process ideas include: 

TT 

TT 

Convection oven 

Collector 

TRC 

TRC 

Air fan 

• Soldering iron temperature control (blowing air over tip with variable-speed fan). 

• Pneumatic piston height control (using lengths of PVC pipe to build a simple piston/cylinder which 

may be used to lift small weights using modest air pressures). A good way to control air pressure to 

the piston is to route the I/P transducer’s output to a volume booster relay and let the relay’s output 

directly drive the piston. Piston height may be sensed using a flexible water tube attached to the piston 

rod, running to a stationary pressure transmitter. 

• Inverted pendulum balance. Note: this is an advanced project! 

70 

JC 

(PWM) 

JC 

(VFD or 

PWM)

Lab Exercise – selecting components and planning the system 

One of the most common problems students encounter when building any working system, whether it be 

a circuit on a solderless breadboard or an instrument loop spanning an entire room, is properly connecting and 

configuring all components. An unfortunate tendency among most students is to simply start connecting 

parts together, essentially designing the system as they go. This usually leads to improperly-connected 

components and non-functioning systems, sometimes with the result of destroying components due to those 

improper connections! 

An alternative approach is to plan ahead by designing the system before constructing it. This is easily 

done by sketching a diagram showing how all the components should interconnect, then analyzing that 

diagram and making changes before connecting anything together. When done as a team, this step ensures 

everyone is aware of how the system should work, and how it should go together. The resulting “prototype” 

diagram need not be complex in detail, but it should be detailed enough for anyone to see which component 

terminals (and ports) connect to terminals and ports of other devices in the system. For example, your 

team’s prototype sketch should be clear enough to determine all DC electrical components will have the 

correct polarities. If your proposed system contains a significant amount of plumbing (pipes and tubes), 

your prototype sketch should show all those connections as well. 

Your first step should be selecting proper field instruments from the instrument storage area to use in 

building your system. In this particular lab, you are looking for a transmitter suitable for measuring your 

process variable, and likely an I/P converter used to convert the controller’s 4-20 mA output signal into 

an air pressure that a control valve may operate on. Electronic process controllers are in several locations 

throughout the lab, ready to be used for controlling processes. Your instructor will help you select appropriate 

instruments for the process you have chosen. 

You may also need a data acquisition unit, or DAQ to function as a trend recorder. When used with a 

personal computer and connected properly to the loop circuit, a DAQ unit will provide graphical displays 

of loop variables over time. Students usually find the connection of a DAQ unit to their loop controller to 

be the trickiest part of their loop wiring. You will need to consult the manufacturer documentation on the 

DAQ unit as well as the field instruments and controller in order to figure out how to wire them together. 

You will find your teammates who have already taken the Measurement course series will be very helpful 

in showing you how to check, configure, calibrate, and install the measuring instrument(s) you will need for 

your process! 

Your team’s prototype sketch is so important that the instructor will demand you provide this plan 

before any construction on your team’s working system begins. Any team found constructing their system 

without a verified plan will be ordered to cease construction and not resume until a prototype plan has been 

drafted and approved! Each member on the team should have ready access to this plan (ideally possessing 

their own copy of the plan) throughout the construction process. Prototype design sketching is a skill and 

a habit you should cultivate in school and take with you in your new career. 

Planning a functioning system should take no more than an hour if the team is working 

efficiently, and will save you hours of frustration (and possible component destruction!). 

71

Lab Exercise – building the system 

The Instrumentation lab is set up to facilitate the construction of working instrument “loops,” with over 

a dozen junction boxes, pre-pulled signal cables, and “racks” set up with 2-inch vertical pipes for mounting 

instruments. These racks also provide structure for building physical processes, with more than enough 

weight-bearing capacity to hold any process vessels and equipment. The only wires you should need to 

install to build a working system are those connecting the field instrument to the nearest junction box, and 

then small “jumper” cables connecting different pre-installed cables together within intermediate junction 

boxes. 

After getting your prototype sketch approved by the instructor, you are cleared to begin building your 

system. Instruments attach to 2-inch pipes using special brackets and U-bolts. These brackets and U-bolts 

are located in the instrument storage area. You will also need to install liquid-tight flexible conduit between 

the instrument(s) and the nearest junction box to route signal wires through. Conduit and fittings are 

located in a drawer in the back of the lab near the instrument storage area. This ensures your installation 

will have a professional appearance with no exposed signal wiring. 

Select a specific loop controller for your system. Your instructor may choose the controller for your 

team, to ensure you learn more than one type of controller during the course of a quarter. 

Finally, your process control system needs to have a loop number, so all instruments may be properly 

labeled. This loop number needs to be unique, so that another team does not label their instruments and 

cables the same as yours. One way to make your loop number unique is to use the equivalent resistor colorcode 

value for your team’s color in the loop number. For example, if you are the “Red” team, your loop 

number could be “2”. 

Common mistakes: 

• Neglecting to consult the manufacturer’s documentation for field instruments (e.g. how to wire them, 

how to calibrate them). 

• Mounting the field instrument(s) in awkward positions, making it difficult to reach connection terminals 

or to remove covers when installed. 

• Improper pipe/tube fitting installation (e.g. trying to thread tube fittings into pipe fittings and visaversa). 

• Failing to tug on each and every wire where it terminates to ensure a mechanically sound connection. 

• Students working on portions of the system in isolation, not sharing with their teammates what they 

did and how. It is important that the whole team learns all aspects of their system! 

Building a functioning process complete with instrumentation for control typically takes 

one or two sessions (3 hours each) if all components are readily available and the team is 

working efficiently! 

72

Lab Exercise – documenting the system 

Each student must sketch their own loop diagram and their own P&ID for their team’s system, following 

proper ISA conventions. The P&ID documents the flow of fluid and materials in your process plus the 

general control strategy. The loop diagram documents all wiring and tube connections between instruments. 

Although the two diagrams reinforce one another and might possibly be combined into one, the industry 

standard is to use two separate diagrams. 

Sample loop diagrams are shown in the next question in this worksheet. These loop diagrams must be 

comprehensive and detailed, showing every wire connection, every cable, every terminal block, range points, 

etc. The principle to keep in mind here is to make the loop diagram so complete and unambiguous that 

anyone can follow it to see what connects to what, even someone unfamiliar with industrial instrumentation. 

In industry, loops are often constructed by contract personnel with limited understanding of how the system 

is supposed to function. The loop diagrams they follow must be so complete that they will be able to connect 

everything properly without necessarily understanding how it is supposed to work. 

Every instrument and every signal cable in your loop needs to be properly labeled with an ISA-standard 

tag number. An easy way to do this is to wrap a short piece of masking tape around each cable (and placed 

on each instrument) then writing on that masking tape with a permanent marker. Although no industry 

standard exists for labeling signal cables, a good recommendation is to label each two-wire cable with the 

tag number of the field instrument it goes to. Thus, every length of two-wire cable in a pressure transmitter 

circuit should be labeled “PT-x” (where “x” is the loop number), every flow control valve should be labeled 

“FV-x”, etc. Remember that the entire loop is defined by the process variable it measures: if the PV is 

temperature then the transmitter with be a TT, the control valve will be a TV, the controller with be a TC, 

etc. 

When your entire team is finished drafting your individual loop diagrams, call the instructor to do an 

inspection of the loop. Here, the instructor will have students take turns going through the entire loop, 

with the other students checking their diagrams for errors and omissions along the way. During this time 

the instructor will also inspect the quality of the installation, identifying problems such as frayed wires, 

improperly crimped terminals, poor cable routing, missing labels, lack of wire duct covers, etc. The team 

must correct all identified errors in order to receive credit for their system. 

After successfully passing the inspection, each team member needs to place their loop diagram in the 

diagram holder located in the middle of the lab behind the main control panel. When it comes time to 

troubleshoot another team’s system, this is where you will go to find a loop diagram for that system! 

The P&ID’s will be submitted to the instructor for inspection as well, but the process itself need not 

be inspected again. 

Common mistakes: 

• Forgetting to label all signal wires (see example loop diagrams). 

• Forgetting to label all field instruments with their own tag names (e.g. PT-83). 

• Forgetting to note all wire colors. 

• Forgetting to put your name on the loop diagram! 

• Basing your diagram off of a team-mate’s diagram, rather than closely inspecting the system for yourself. 

• Not placing loop sheet instruments in the correct orientation (field instruments on the left, control room 

instruments on the right). 

Creating and inspecting accurate loop diagrams should take no more than one full lab 

session (3 hours) if the team is working efficiently! Creating and inspecting accurate P&IDs 

will take more time, but not an entire lab session (3 hours). 

73

Lab Exercise – operating the system 

All networked loop controllers in the lab (DCS, DDC, PLC, single-loop networked) provide graphing 

functionality so that you may plot your process variable (PV) and output values over time. This graphical 

data is essential for tuning PID-controlled loops. If you happen to be using a controller that does not provide 

graphing capability, your team must attach a trend recorder and/or a data acquisition unit (plus a personal 

computer) to the necessary signal cables so that these values are recorded over time. 

PID tuning is a subject worthy of its own course, and so you will not be expected to achieve perfect 

control on your process. You will find, however, that one of the best ways to learn PID tuning is by 

“playing” with your process as it responds to different tuning parameters entered into the loop controller. 

The expectation for “good control behavior” in the context of this lab exercise is for the loop to exhibit 

response that is no less stable following large setpoint changes than the classic “quarter-wave damping” 

described by Ziegler and Nichols in 1942. 

Most student-built processes are quite safe to operate. However, if your process harbors any unique 

hazards (e.g. overflowing water may present a slip hazard, overheated oven may cause materials to smoke 

or burn), you must be aware of these hazards and limit everyones’ exposure to them. All team members 

for each process must be familiar with the inherent hazards of their process and how to mitigate them. 

One operational step to help avoid problems is to configure the controller for setpoint limits preventing the 

setpoint value from being placed at “dangerous” values in automatic mode. Just what these setpoint limit 

values should be set to varies with the process and the team’s experience operating it. 

As your time with the process builds, you will no doubt arrive at ideas for improving it. Feel free to 

work with your team to optimize the process in any way you see fit. The goal is to have your process as 

robust and “problem-free” as possible for other teams to use it in later coursework! 

After you have built and tuned your process, you should identify and configure alarm values for the 

controller’s PV display. Most controllers have PV alarm capability built in, signaling a condition of excessive 

or insufficient PV if those alarm points are ever tripped. You need to set at least a high alarm on the PV so 

that when other teams come after you to re-tune your process, they have some “guidepost” showing them 

what PV value(s) they should not exceed! If your team has enough time, feel free to connect an actual alarm 

indicator light and/or audible buzzer to your control system that turns on (and latches) if an alarm point is 

exceeded. 

A tendency of students when they first learn to tune PID control loops is to proceed carelessly because 

they know the “toy” processes they are learning to tune aren’t going to harm anything if their PVs go out 

of bounds. While this assumption might be true for your team’s process, it is not good to allow others to 

proceed as such and form bad habits. Thus, the inclusion of alarm point(s) on your process PV – especially 

if connected to some form of signaling device that is annoying and/or embarrassing to trip such as a loud 

buzzer – makes for a better teaching tool for others learning PID tuning! 

74

A crude closed-loop PID tuning procedure 

Tuning a PID controller is something of an art, and can be quite daunting to the novice. What follows 

is a primitive (oversimplified for some situations!) procedure you can apply to many processes. 

Step 1 

Understand the process you are trying to control. If you do not have a fundamental grasp on the nature 

of the process you’re controlling, it is pointless – even dangerous – to change controller settings. Here is a 

simple checklist to cover before touching the controller: 

• What is the process variable and how is it measured? 

• What is the final control element, and how does it exert control over the process variable? 

• What safety hazards exist in this process related to control (e.g. danger of explosion, solidification, 

production of dangerous byproducts, etc.)? 

• How far am I allowed to “bump” the process while I tune the controller and monitor the response? 

• How is the controller mode switched to “manual,” just in case I need to take over control? 

• In the event of a dangerous condition caused by the controller, how do you shut the process down? 

Step 2 

Understand what the settings on the controller do. Is your controller configured for gain or proportional 

band? Minutes per repeat or repeats per minute? Does it use reset windup limits? Does rate respond to 

error or PV alone? You had better understand what the PID values do to the controller’s action if you 

are going to decide which way (and how much) to adjust them! Back in the days of analog electronic and 

pneumatic controllers, I would recommend to technicians that they draw little arrow symbols next to each 

adjustment knob showing which way to turn for more aggressive action – this way they wouldn’t get mixed 

up figuring out gain vs PB, rep/min vs min/rep, etc.: all they had to think of is “more” or “less” of each 

action. 

Step 3 

Manually “bump” the manipulated variable (final control element) to learn how the process responds. 

Right now, you are the controller! What you need to do is adjust the process to learn how it responds: 

is it an integrating process, a self-regulating process, or a runaway process? Is there significant dead time 

or hysteresis? Is the response linear and consistent? Many process control problems are caused by factors 

other than the controller, and this “manual test” step is a key diagnostic technique for assessing these other 

factors. 

Step 4 

Set the PID constants to “minimal” settings and switch to automatic mode. This means gain less than 

1, no integral action (0 rep/min or maximum min/rep), no derivative action, and no filtering. 

Step 5 

“Bump” the setpoint and watch the controller’s response. This tests the controller’s ability to manage 

the process on its own. What you want is a response that is reasonably fast without overshooting or 

undershooting too much, and without undue cycling. The nature of the process and the constraints of 

quality standards will dictate what is “too much” response time, over/undershoot, and cycling. 

Step 6 

Increase or decrease the control action aggressiveness according to the results of Step 5. 

Step 7 

Repeat steps 5 and 6 for P, I, and D, one at a time, in that order. In other words, tune the controller 

first to act as a P-only controller, then add integral (PI control), then derivative (PID), each as needed. 

75

Caveats 

The procedure described here is very crude, and should only be applied as a student’s first foray into 

PID tuning, on a safe “demonstration” process. It assumes that the process responds predominantly to 

proportional (P-only) action, which may not be true for some processes. It also gives no specific advice for 

tuning based on the results of step 3, which is the mark of an experienced PID tuner. With study, practice, 

and time, you will learn what types of processes respond best to P, I, and D actions, and then you will be 

able to intelligently choose what parameters to adjust, and what closed-loop behaviors to look for. 

76

Lab questions – (reviewed between instructor and student team in a private session) 

• Selection and Initial Testing 

• Explain how to simply test the transmitter for proper operation prior to actually starting up the process 

• Explain how to simply test the final control element for proper operation prior to actually starting up 

the process 

• Explain and demonstrate how to set the tuning parameters (P, I, and D) of the controller 

• Identify and explain the distinction between direct and reverse control modes in the loop controller 

• Identify some of the main loads in your process, and explain how they may be varied while the process 

is running 

• Commissioning and Documentation 

• Demonstrate how to isolate potentially hazardous energy in your system (lock-out, tag-out) and also 

how to safely verify the energy has been isolated prior to commencing work on the system 

• Explain and demonstrate how to set the proper engineering units for the controller’s process variable 

(PV) and setpoint (SP) indicators 

• Explain (step by step) how to secure an operating (automatic mode) control loop to calibrate the process 

transmitter without shutting down the process 

• Explain (step by step) how to secure an operating (automatic mode) control loop to stroke and calibrate 

the control valve without shutting down the process 

• Demonstrate the use of a loop calibrator to measure the 4-20 mA signal output by the transmitter 

• Demonstrate the use of a loop calibrator to simulate the 4-20 mA signal coming from the transmitter 

• Demonstrate the use of a loop calibrator to stroke the control valve 

• Mental math (no calculator allowed!) 

• Convert a proportional band value into a gain value, or visa-versa 

• Convert a repeats/(minute or second) integral value into a (minutes or seconds)/repeat integral value, 

or visa-versa 

• Calculate the pneumatic pressure in a 3-15 PSI range corresponding to x percent. 

• Calculate the electrical current in a 4-20 mA range corresponding to x percent. 

• Calculate the electrical voltage in a 1-5 volt range corresponding to x percent. 

• Calculate the percentage value of a pneumatic pressure signal x PSI in a 3-15 PSI range. 

• Calculate the percentage value of an electrical current signal x mA in a 4-20 mA range. 

• Calculate the percentage value of an electrical voltage signal x volts in a 1-5 volt range. 

• Diagnostics 

• “Virtual Troubleshooting” – referencing their system’s diagram(s), students propose diagnostic tests 

(e.g. ask the instructor what a meter would measure when connected between specified points; ask the 

instructor how the system responds if test points are jumpered) while the instructor replies according 

to how the system would behave if it were faulted. Students try to determine the nature and location 

of the fault based on the results of their own diagnostic tests. 

• Explain how to distinguish an “open” cable fault from a “shorted” cable fault using only a voltmeter 

(no current or resistance measurement, but assuming you are able to break the circuit to perform the 

test) 

• Identify the effect of improper controller action (direct versus reverse) on an automatically-controlled 

process 

• Explain how to use the “manual” mode of a process controller as a diagnostic test to check for problems 

in a control system 

file i01558 

77

Question 92 

The Rules of Fault Club 

(1) Don’t try to find the fault by looking for it – perform diagnostic tests instead 

(1) Don’t try to find the fault by looking for it – perform diagnostic tests instead! 

(3) The troubleshooting is over when you have correctly identified the nature and location of the fault 

(4) It’s just you and the fault – don’t ask for help until you have exhausted your resources 

(5) Assume one fault at a time, unless the data proves otherwise 

(6) No new components allowed – replacing suspected bad components with new is a waste of time and 

money 

(7) We will practice as many times as we have to until you master this 

(8) Troubleshooting is not a spectator sport: you have to troubleshoot! 

These rules are guaranteed to help you become a better troubleshooter, and will be consistently 

emphasized by your instructor. 

78

79 

Loop Diagram: Revised by: Date: 

Tag # Description Manufacturer Model Input range Output range Notes 

Loop diagram template

Loop diagram requirements 

Perhaps the most important rule to follow when drafting a loop diagram is your diagram should be 

complete and detailed enough that even someone who is not an instrument technician could understand 

where every wire and tube should connect in the system! 

• Instrument “bubbles” 

• Proper symbols and designations used for all instruments. 

• All instrument “bubbles” properly labeled (letter codes and loop numbers). 

• All instrument “bubbles” marked with the proper lines (solid line, dashed line, single line, double lines, 

no lines). 

• Optional: Calibration ranges and action arrows written next to each bubble. 

• Text descriptions 

• Each instrument documented below (tag number, description, etc.). 

• Calibration (input and output ranges) given for each instrument, as applicable. 

• Connection points 

• All terminals and tube junctions properly labeled. 

• All terminal blocks properly labeled. 

• All junction (“field”) boxes shown as distinct sections of the loop diagram, and properly labeled. 

• All control panels shown as distinct sections of the loop diagram, and properly labeled. 

• All wire colors shown next to each terminal. 

• All terminals on instruments labeled as they appear on the instrument (so that anyone reading the 

diagram will know which instrument terminal each wire goes to). 

• Cables and tubes 

• Single-pair cables or pneumatic tubes going to individual instruments should be labeled with the field 

instrument tag number (e.g. “TT-8” or “TY-12”) 

• Multi-pair cables or pneumatic tube bundles going between junction boxes and/or panels need to have 

unique numbers (e.g. “Cable 10”) as well as numbers for each pair (e.g. “Pair 1,” “Pair 2,” etc.). 

• Energy sources 

• All power source intensities labeled (e.g. “24 VDC,” “120 VAC,” “20 PSI”) 

• All shutoff points labeled (e.g. “Breaker #5,” “Valve #7”) 

80

81 

Loop Diagram: Furnace temperature control 

TE 

205 

TV 

205 

Process area 

1 

2 

Resistor 

TT 

205 

TIC-205 Controller Siemens PAC 353 


I /P 

AS 20 PSI 

Valve #15 

Column #8 

TT-205 Temperature transmitter Rosemount 444 

TY-205a 

TY-205b 

Tube TV-205 

TV-205 Control valve Fisher Easy-E 3-15 PSI 

Revised by: Mason Neilan 

Date: 

Field panel Control room panel 

JB-12 

CP-1 

0-1500 o F 0-1500 o F 

Yel Red 

Red 

Red 

Blk 

TY 

205b 

TB-15 

3 

4 

TB-15 

TB-11 

Cable TT-205 Cable TT-205 

1 

2 

TB-11 

Vishay 250 Ω 

Fisher 

Red 

Blk 

Cable TY-205b 

546 

Blk 

5 

6 

3 

4 

TY 

205a 

Cable TY-205b 

7 

22 

21 

19 

18 

H 

N 

TIC 

205 

ES 120 VAC 

Breaker #4 

Panel L2 

TE-205 Thermocouple Omega Type K Ungrounded tip 

Wht/Blu 

Wht/Blu 

Cable 3, Pr 1 

Blu Blu 

Wht/Org 

Wht/Org 

Cable 3, Pr 2 

Org Org 


Red 

Blk 

Red 

Blk 

Red 

Blk 

0-1500 o F 4-20 mA 

1-5 V 0-1500 o F 

4-20 mA 3-15 PSI 

0-100% 

Red 

Blk 

Red 

Blk 

Blk 

Wht 

Upscale burnout 

Reverse-acting control 

Fail-closed 

April 1, 2007 

Sample Loop Diagram (using a single-loop controller)

82 

Loop Diagram: Blue team pressure loop Revised by: Duncan D.V. 

Date: April 1, 2009 

H 

L 

PV 

73 6 

PT 

73 6 

Field process area 

Red 

Blk 

Cable PT-6 PT-73 

Red 

DCS cabinet 


Fisher 

Field panel JB-25 

TB-52 

TB-52 

Control valve Fisher Vee-ball 

Blk 

Cable 4, Pr 1 

Cable 4, Pr 8 

Red 

Blk 

Red 

Blk 

TB-80 

11 

12 

TB-80 

PT-73 PT-6 Pressure transmitter Rosemount 3051CD 0-50 PSI 4-20 mA 

PIC-73 PIC-6 

PY-73 PY-6 

PV-73 PV-6 

0-50 PSI 

Tube PV-6 

Controller 


I /P 

PY 

73 6 

AS 20 PSI 

Red 

Blk 

Red 

Cable PV-6 PV-73 

Blk 

846 

1 

2 

15 

16 

Red 

Blk 

Red 

Blk 

29 

30 

Red 

Blk 

Red 

Emerson DeltaV 4-20 mA 4-20 mA 

Blk 

4-20 mA 3-15 PSI 

Red 

Cable PT-6 PT-73 

Blk 

Red 

Cable PV-73 PV-6 

Blk 

11 

12 

11 

12 

Card 4 

Channel 6 

Analog 

input 

PIC 

73 6 

Card 6 

Channel 6 

Analog 

output 

0-50 PSI 

HART-enabled input 

Direct-acting control 

3-15 PSI 0-100% Fail-open 

Sample Loop Diagram (using DCS controller)

83 

file i00654 

Loop Diagram: Sludge tank level control Revised by: I. Leaky Date: April 1, 2008 

Process area 

Bulkhead panel 

B-104 

Control panel CP-11 

(vent) 

LV 

24 

H 

L 

LT 

24 

In 

Out 

A.S. 21 PSI 

Tube LV-24 

Tube LT-24a Tube LT-24b 

14 

Tube LV-24 

Tube LV-24 


LT-24 Level transmitter Foxboro 13A 25-150 "H 2O 3-15 PSI 

LIC-24 Controller 

Foxboro 130 

3-15 PSI 3-15 PSI 

C 

LIC 

24 

D 

Supply 

A.S. 21 PSI 

LV-24 Control valve Fisher Easy-E / 667 3-15 PSI 0-100% Fail closed 

Sample Loop Diagram (using pneumatic controller)

Question 93 

Connect an “ice-cube” relay to a DC voltage source and a switch such that the relay will energize when 

the switch is closed. All electrical connections must be made using a terminal strip (no twisted wires, crimp 

splices, wire nuts, spring clips, or “alligator” clips permitted). 

This exercise tests your ability to properly interpret the “pinout” of an electromechanical relay, properly 

wire a switch to control a relay’s coil, and use a terminal strip to organize all electrical connections. 

Relay socket 

Relay 

Terminal strip 

Switch 

The following components and materials will be available to you during the exam: assorted “ice cube” 

relays with DC-rated coils and matching sockets ; assorted switches ; terminal strips ; lengths of 

hook-up wire ; battery clips (holders). 

You will be expected to supply your own screwdrivers and multimeter for assembling and testing the 

circuit at your desk. The instructor will supply the battery(ies) to power your circuit when you are ready 

to see if it works. Until that time, your circuit will remain unpowered. 

Study reference: the “Control Relays” section of Lessons In Industrial Instrumentation. 

file i03772 

84

Answer 1 

Answer 2 

Partial answers: 

Answers 

Explain why instrument transformers (PTs and CTs with voltage step-down and current step-down 

ratios) are used to connect the PQM to the power system conductors. The instrument transformers 

provide both signal reduction and galvanic isolation between the PQM and the high-voltage, 

high-current power line conductors. 

Assuming a phase-to-neutral voltage on “B” phase of 7155 volts AC, calculate the voltage seen between 

the PQM instrument’s V2 and VN terminals. 119.25 volts 

Answer 3 

Answer 4 

One disadvantage is that while using software such as AMS to view and/or edit HART instrument 

parameters from the control room display, you do not get the same sort of verification of having the right 

instrument as you do when connecting a handheld HART communicator directly to the instrument! 

Answer 5 

Answer 6 

Each line beginning with a letter “C” is a comment, placed there strictly for the benefit of any human 

being reading the program. Comments are ignored by the controller as it executes the code. 

The .LT. operator stands for “Less Than” while the .GT. operator stands for “Greater Than” and the 

.EQ. operator stands for “Equal To”. 

The singular GOTO instruction causes the program to loop, endlessly repeating the entire program. 

Answer 7 

Each line beginning with a letter “C” is a comment, placed there strictly for the benefit of any human 

being reading the program. Comments are ignored by the controller as it executes the code. 

The .LE. operator stands for “Less Than Or Equal To” while the .GT. operator stands for “Greater 

Than”. 

Answer 8 

Based on the first measurement (only), we could conclude the wiring fault may be an “open” in either 

cable 30 or in cable 41. 

After taking the second measurement, we must conclude the fault is an “open” in cable 41 (or an “open” 

fault in the valve positioner). 

Answer 9 

Answer 10 

This mis-calibration will result in the actual flash vessel pressure being greater than it should be. 

85

Answer 11 

Partial answer: 

• AI 1-5 VDC Analog input, requires external 250 Ω resistor and loop power supply 

• AI 4-20 mADC 

• AI 4-20 mADC w/ HART Analog input, provides loop power and HART communication ability 

• AO 4-20 mA 

• AO w/ HART 

• DI 24VDC dry contact Discrete input, provides power for switch circuit 

• DI 24VDC isolated 

• DI 120VAC isolated 

• DO 24VDC high side 

Answer 12 

Answer 13 

Answer 14 

Answer 15 

Answer 16 

Answer 17 

Answer 18 

Answer 19 

Answer 20 

Answer 21 

Answer 22 

Answer 23 

Answer 24 

Answer 25 

Answer 26 

Answer 27 

86

Answer 28 

Answer 29 

• Pressure gauge 

• LRV = 0 PSI 

• URV = 100 PSI 

• Test pressure = 65 PSI 

• Instrument indication = 67 PSI 

• Error = +2 % of span 

• Weigh scale 

• LRV = 0 pounds 

• URV = 40,000 pounds 

• Test weight = 10,000 pounds 

• Instrument indication = 9,995 pounds 

• Error = -0.0125 % of span 

• Thermometer 

• LRV = -40 o F 

• URV = 250 o F 

• Test temperature = 70 o F 

• Instrument indication = 68 o F 

• Error = -0.69 % of span 

• pH analyzer 

• LRV = 4 pH 

• URV = 10 pH 

• Test buffer solution = 7.04 pH 

• Instrument indication = 7.13 pH 

• Error = +1.5 % of span 

Measured level Percent of span Output signal 

(feet) (%) (mA) 

1.6 80 16.8 

0.3875 19.375 7.1 

0.8 40 10.4 

87

Answer 30 

Hysteresis and dead band are not exactly the same type of calibration error, but they are closely related. 

“Dead band” refers to a range of instrument measurement during reversal of input where the output does not 

change at all. A common example of this is a “loose” steering system in an automobile, where the steering 

wheel must be turned excessively to take up “backlash” (mechanical slack) in the linkage system. 

Hysteresis refers to the situation where a reversal of input causes an immediate, but not proportionate, 

reversal of output. This is commonly seen in air-actuated valves, where air pressure acts against the action of 

a large spring to precisely position a valve mechanism. Ideally, the valve mechanism will move proportionally 

to the air pressure signal sent to it, and this positioning will be both repeatable and accurate. Unfortunately, 

friction in the valve mechanism produces hysteresis: a different air pressure signal may be required to position 

the valve mechanism at the same location opening versus closing, but unlike dead band, any amount of signal 

reversal (change of direction: increasing vs. decreasing) will cause the valve to move slightly. 

Compare the following transfer function graphs to understand the difference between hysteresis and 

dead band: 

Dead band: 

Hysteresis: 

Output 

Output 

Ideal instrument response 

(no hysteresis or dead band) 

Output 

going 

down going 

up 

Input 

going 

down 

Input 

going 

up 

Input 

Dead 

band 

Output 

Output 

going 

down 

Input 

going 

down 

Input 

going 

up 

going 

up 

Dead 

band 

Both dead band and hysteresis are characteristically mechanical phenomena. Electronic circuits rarely 

exhibit such “artifacts” of measurement or control. Dead band and hysteresis are more often found together 

than separately in any instrument. 

Interestingly, both effects are present in magnetic circuits. The magnetization curves for typical 

transformer core steels and irons are classic examples of hysteresis, whereas the magnetization curve for 

ferrite (in the saturation region) is quite close to being a true representation of deadband. 

Answer 31 

I’ll answer the question with a scenario of my own: suppose it is discovered that some patients suffered 

complications after taking drugs manufactured by this company, and that the particular batch of suspect 

drugs were processed in this very same vessel about 6 months ago? Now imagine that this temperature 

recording instrument gets routinely calibrated once a month. See the problem? 

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This instrument has a zero shift error, but not a span shift or linearity error. 

Ideal transfer function: 

Output 

(mA) 

Actual transfer function: (zero error) 

Output 

(mA) 

20 

16 

12 

8 

4 

0 

20 

16 

12 

8 

4 

0 

0 

0 

25 

25 

90 

50 

75 

Input 

(PSI) 

ideal 

50 

75 

Input 

(PSI) 

100 

100 

actual

A span error would look something like this (wrong slope): 

Output 

(mA) 

20 

16 

12 

8 

4 

0 

ideal 

0 

25 

actual 

50 

75 

Input 

(PSI) 

A linearity error would look something like this (not a straight line): 

Output 

(mA) 

20 

16 

12 

8 

4 

0 

ideal 

0 

25 

50 

75 

Input 

(PSI) 

100 

actual 

A zero error is usually correctable by simply adjusting the “zero” screw on an analog instrument, without 

making any other adjustments. Span errors, by contrast, usually require multiple adjustments of the “zero” 

and “span” screws while alternately applying 0% and 100% input range values to check for correspondence 

at both ends of the linear function. 

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Answer 64 

Chances are there is something wrong with the ID fan, causing it to move less air than it should. 

Alternatively, the FD fan could be at fault, spinning faster than it should. 

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100

Answer 65 

Diagnostic test Yes No 

√ 

Measure AC line voltage 

√ 

Measure DC power supply output voltage 

√ 

Inspect PID tuning parameters in controller 

√ 

Check pressure transmitter calibration 

√ 

Measure transmitter current signal 

√ 

Put controller into manual mode and move valve 

√ 


√ 


Moving the valve in manual mode will be a worthwhile test only if you also check the gauge’s and 

controller’s indications of pressure with the valve in a different position. Both indications should change 

with a change in valve position. 

Answer 66 

Answer 67 


√ 

PG-108 calibration error 

√ 

PT-33 calibration error 

√ 

PIC-33 left in manual mode 

√ 

PY-33a calibration error 

√ 

PY-33b calibration error 

Students are often surprised to find that a transmitter calibration error would not cause this problem. 

A calibration error in the LT would cause the actual steam drum level to drift off setpoint, but with this 

being the only problem the controller would still register right on setpoint! 

A vital “next test” is to check the controller output, to see what it is trying to tell the valve to do. It 

should be commanding the valve to open up. If not, the controller definitely has some sort of problem (or is 

in manual mode). 

Answer 68 

There is a lot to consider when planning the As-Found calibration test. What I am looking for here is 

a complete step-by-step procedure describing a safe and logical way to conduct the test without causing the 

circuit breaker to trip. 

Answer 69 

A good step to take next is to figure out whether the problem is on the output side of the control 

system or on the input side of the control system. Is the slow pressure trend real, and the control valve not 

responding as quickly as it should? Is the pressure actually changing quickly, but the measurement side of 

the system not accurately reporting it as it should? 

Probably the best first-step here is to actually go to the control valve and observe how fast it responds 

to step-changes from the controller (manual mode). 

Answer 70 

This is an example of a process with interacting control loops! 

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This is a graded question – no answers or hints given! 

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Answer 92 

Your loop diagram will be validated when the instructor inspects the loop with you and the rest of your 

team. 

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INST 262 (DCS and Fieldbus), section 2 Lab Automatically ...

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