MultiRAE - Shawcity Limited

MultiRAE 

MULTIPLE GAS MONITOR 

(PGM - 50) 

DIAGNOSTIC AND SERVICE MANUAL 

(Document No: 008-4011-000) 

Rev. D. 

RAE SYSTEMS INC. 

1339 Moffet Park Drive 

Sunnyvale, CA 94089 

January 2004 

1

I. Objective: 

This document provides detailed diagnostic and service procedures for service personnel 

in the factory and field service center. The procedure allows trained service personnel to 

perform a set of diagnostic tests to determine if the Unit Under Test (UUT) is functioning 

properly and performing within the specification. The procedure also helps to diagnose 

the possible causes of failures and suggest a number of corrective actions. 

II. Diagnostic and Service Requirements: 

1) In order to perform the PGM-50 diagnostic and service procedures, the service person 

should be very familiar with the procedure described in the PGM-50 Operation and 

Maintenance Manual (RAE Part Number: 008-4001). 

2) The following equipment is required: 

PC with Windows 3.1/ Windows 95 or above operating system and serial port. 

Computer interface cable (RAE Part Number 008-3003) 

ProRAE Suite software 

DC power supply (0-10V, 200 mA) 

Multi-meter (0-10VDC, 0-150 mA, 0-10 megaohm) 

20 ohm, 1W resistor 

Flat head screw driver 

#2 phillips screw driver 

Tweezers 

Battery connector with wires 

2

III. Trouble Shooting Guide: 

PGM-50 problems can be grouped into 4 major areas: 

1) Power supply - battery and charger 

2) Sensor and measurement 

3) Electronics 

4) Programming 

The following trouble shooting guide provides a quick reference for typical problems in 

each major area: 

1) Power Supply - Battery and Charger: 

Problem Possible Causes Test Procedures 

Can not turn on unit 1) battery charge is low 

2) battery pack fuse is blown 

3) battery is disconnected from the PCB or the 

battery wire is broken 

4) defective electronics 

1) Test 1.5 & 1.5A 

2) Test 1.1 

3) Test 1.1 

4) Test 3.1 

“bAt” message during 

operation 

Unit runs less than 

specified duration: 

Battery is warm during 

normal operation 

Charger light does not turn 

on 

Charger light does not 

change from red to green 

after overnight charging 

2) Sensor and Measurement: 

1) battery charge is low 

2) defective battery voltage measurement circuit 

3) excessive loading on the battery 

4) defective battery 

1) excessive loading on the battery 

2) memory effect of Ni-Cd battery 

3) old or defective Ni-Cd battery pack 

4) defective charger 

5) incomplete charging 

1) Test 1.5 & 1.5A 

2) Test 1.4 

3) Test 1.3 

4) Test 1.5 & 1.5A 

1) Test 1.3 

2) Test 1.5 & 1.5A 

3) Test 1.5 & 1.5A 

4) Test 1.6 

5) Test 1.7 & 1.5A 

1) excessive loading on the battery 1) Test 1.3 

1) broken wire inside PGM-50 

2) alkaline battery is used inside PGM-50 


4) bad LED 


2) defective charging circuit 

3) bad green LED 

4) bad battery 

5) ambient temperature too high or low 

1) Test 1.6 

2) Test 1.7 

3) Test 1.6 

4) Test 3.2 

1) Test 1.6 

2) Test 1.7 

3) Test 3.2 

4) Test 1.5 & 1.5A 

5) Test 1.8 


Unit turns on, shows 

“Configuration changed” 

message 

1) sensor added or removed 

2) sensor is disconnected or loose from socket 

3) defective sensor 

1) Test 2.3 

2) Test 2.3 

3) Test 2.3 

Sensor is installed but not 

showing on LCD 

1) sensor is disconnected or loose from the socket 


3) Sensor disabled 

1) Test 2.3 

2) Test 2.3 

3) Test 2.3 

3

No response or low 

response to gas input 

Slow response to gas input 

Erratic reading 

Non-zero background 

reading 

“CAL Err” message during 

calibration 

Flashing “CAL” message 

during normal operation 

Readings consistently 

wrong when exposed to gas 

During normal operation, 

“pump” message flashing 

“xxx installed 

bias error” message on 

LCD 

Calibrates OK, but LEL or 

VOC readings off by 

constant percentage. 

“Lamp” message during 

operation 

1) sensor input is blocked or dirty filter 

2) defective sensor module 


4) weak, or leaking pump 

5) sensor cover plate missing, loose, or misaligned 

6) empty sensor position 

1) sensor input is blocked or dirty filter 


3) sensor has inherently slow response time 

4) weak or leaking pump 

5) sensor cover plate missing, loose, or misaligned 

6) empty sensor position 

1) incorrect calibration 



4) weak or leaking pump 

1) dirty filter 

2) incorrect zero calibration or zero drift 


4) non-zero background 

5) carbon filter saturated or not installed 

1) incorrect calibration 

2) low gas pressure in gas cylinder 

3) defective sensor module or weak lamp 

4) leak in flow path 


1) Test 2.1 

2) Test 2.4 

3) Test 2.4 

4) Test 2.2 

5) Test 2.1 

6) Test 2.1 

1) Test 2.1 

2) Test 2.4 

3) Test 2.4 

4) Test 2.2 

5) Test 2.1 

6) Test 2.1 

1).Test 2.5 

2) Test 2.4 

3) Test 2.4 

4) Test 2.2 

1) Test 2.1 

2) Test 2.6 

3) Test 2.4 

4) Test 2.6 

5) Test 2.1 

1) Test 2.5 

2) Test 2.5 

3) Test 2.4 

4) Test 2.1 

5) Test 2.4 

1) excessive negative zero drift of sensor 1) Test 2.6 

1) incorrect span calibration 


3) incorrect correction factor 

1) Gas inlet blocked or no connection to inlet port 

2) weak or inoperative pump 

3) pump stall threshold needs adjustment 

1) bias switch in wrong position for Toxic1 sensor 


1) Wrong calibration or measurement gas selection 

2) Incorrect lamp selected 

3) incorrect dilution ratio 

1) dirty PID sensor or lamp 

2) weak or defective lamp 

3) Lamp fail threshold adjustment needed 

1) Test 2.5 

2) Test 2.4 

3) Test 4.5 

1) Test 2.1 

2) Test 2.2 

3) Test 2.7 

1) Test 2.8 

2) Test 2.4 

1) Test 4.5 

2) Test 4.5 

3) Test 4.5 

1) Test 2.9 

2) Test 2.9 

3) Test 2.9 

3) Electronics: 


LED, back light, buzzer or 1) defective component 1) Test 3.2 

vibrator alarm inoperative 

Missing segment on the 

LCD 

1) defective LCD 

2) temperature too low 

3) contrast set too low 

1) Test 3.3 

2) Test 3.3 

3).Test 3.3 

4

Random characters on the 

LCD 

No response to key press or 

can not turn off unit 

Back light does not turn on 

in low ambient light 

1) CPU hang-up 


3) wrong firmware or error in firmware 

4) bad LCD 

5) temperature too high or low 

6) contrast too high or too low 

1) membrane disconnected from PCB 

2) defective membrane keys 

3) CPU hang-up 

1) defective electronics or component 

2) back light threshold needs adjustment 

3) unit configured for manual light turn on 

4) unit plugged into A/C adapter 

1) Test 3.3 

2) Test 3.3 

3) Test 4.1 

4) Test 3.3 

5) Test 3.3 

6) Test 3.3 

1) Test 3.1 

2) Test 3.1 

3) Test 3.1 

1) Test 3.3 

2) Test 3.3 

3) Test 3.3 

4) Test 3.3 

4) Programming 


Unable to put into 

programming mode 

1) unit in display or text mode 

2) configured for password protection 

1) Test 4.2 

2) Test 4.3 

Lost password 1) unit configured for password access 1) Test 4.3 

“Unable to configure port” 1) port not available in this PC 1) Test 4.7 

message from ProRAE-50 

software 

“NAK” message from 

ProRAE-50 program 

1) Cable or connection problem 

2) port configuration problem 

3) PC hardware or operating system problem 

1) Test 4.7 

2) Test 4.7 

3) Test 4.7 

Time out message from 

ProRAE-50 software 

Can’t start data logging 

Shows “----“ instead of 

sensor name, does not 

display reading for sensor 

In data log, no readings for 

a sensor even though 

sensor and values show on 

display 

Unit beeps frequently but 

sensor readings are below 

the alarm limits 

No events recorded in PC 

after downloading data but 

data available in “View 

Datalog” menu. 

Unit beeps once per minute 

for no reason 

1) unit not in “Ready” mode 

2) cable or connection problem 

3) PC hardware or operating system problem 

1) datalogging disabled 

2) non-data logging unit 

1) Test 4.7 

2) Test 4.7 

3) Test 4.7 

1) Test 4.4 

2) Test 4.4 

1) sensor disabled 1) Test 4.5 

1) sensor not configured for data logging 1) Test 4.8 

1) alarm latched 

2) STEL or TWA limits exceeded 

3) low battery 

1) Short sample period causing data to be stored 

before header information written. 

1) Test 4.6 

2) Test 4.6 

3) Test 1.1 

1) Test 4.8 

1) comfort beep option turned on 1) Test 4.8 

IV. 

Diagnostic Mode: 

5

All RAE Systems gas monitors have a Diagnostic Mode for evaluating the condition of 

sensor, lamps, pumps, batteries, etc. This is distinct from the usual diagnostic tests the 

instrument performs automatically during routine start-up. All the usual functions can be 

performed in diagnostic mode, such as calibration and monitor set-up. In diagnostic 

mode all sensor outputs (and most other measured values) are displayed as raw values 

(a/d counts) without corrections or conversion to standard units. The following 

diagnostic procedures will make use of this mode when appropriate. Whenever the 

procedures state “place the unit in diagnostic mode” use the following steps to turn on the 

unit in this special mode. 

Entering diagnostic mode: With the unit turned off, hold down the [Y/+] key. While 

still holding this key down, depress and hold the [MODE] key. Hold both keys down 

until unit beeps and then release both keys. The MultiRAE will display “ON!” followed 

by the software version number, the firmware build date, and then the “Diagnostic Mode” 

message. If you hit the [Y/+] key when Diagnostic Mode is on the screen, the warm-up 

will be significantly shorter. The unit will then go through the normal start-up tests. 

Once the monitor is ready, the display will show raw values for each installed sensor, 

with the word “RAW” in the center of the bottom line of the display. 

In Diagnostic Mode, use [N/-] and [MODE] together; just as in normal mode, to enter the 

Programming Menu. CAUTION: When calibrating in Diagnostic Mode the system does 

not check for a difference between the span and zero calibration points. This can be 

useful if calibrating at a low level, (such as 10 ppm VOC). The user must manually 

verify, from the raw values in air and with calibration gas applied, that the sensors are 

working correctly. Use the [MODE] key alone to step through the special diagnostic 

screens in the following sequence: 

Version 1.xx Version 2.00 Version 3.xx 

Raw Sensor Values Raw Sensor Values Raw Sensor Values 

Sensor names Sensor names Sensor names 

PID Lamp Fail Threshold PID Lamp Fail Threshold RF test 

Battery type / Bias Battery type / Bias PID Lamp Fail Threshold 

PID 1X and 10X Range PID 1X and 10X Range Battery type / Bias 

LCD Contrast Adjustment LCD Contrast Adjustment PID 1X and 10X Range 

LEL Power On/Off Check LEL Power On/Off Check LCD Contrast Adjustment 

Clock/Voltage/Temperature Clock/Voltage/Temperature LEL Power On/Off Check 

Sensor expiration dates Sensor expiration dates Clock/Voltage/Temperature 

Pump Stall Threshold Pump Stall Threshold Sensor expiration dates 

Back Light On/Off Threshold Back Light On/Off Threshold Pump Stall Threshold 

Communicate with PC S/N and pump speed Back Light On/Off Threshold 

Battery deep discharge S/N and pump speed 

Power run down time Power run down time 

Communicate with PC Communicate with PC 

6

Software versions 1.05 and later allow access to the Programming Menu from the 

Diagnostic Mode even if the unit is configured in “Display” or “Text” modes. A valid 

password will be required if the unit has been configured with a password. This feature 

allows users to exit from these modes without using a PC. 

PROGRAMMING MODE 

Press [N] and [MODE] together for 3 seconds to begin. 

Calibrate Monitor 

[Y] to select, [N] to move to next menu, [MODE] to return to Display Mode. 

[Y] selects, [N] skips,[MODE] for next menu 

Fresh Air Calibration 

Multiple Sensor Calibration 

Single Sensor Calibration 

Modify Span Gas Value 

Change LEL/VOC Span Gas 

Change Alarm Limits 

Change High Alarm limit 

Change Low Alarm limit 

Change STEL alarm limit 

Change TWA alarm limit 

View or Change Datalog 

Clear All Data 

Change Datalog Period 

Select Data Type 

View Datalog 

Enable/Disable Datalog 

Change Monitor Setup 

Change Site ID 

Change User ID 

Change Alarm Mode 

Change User Mode 

Change Real Time Clock 

Change Back Light Mode 

Change Password 

Change Pump Speed 

Change Averaging Method 

Change Sensor Configuration 

Change LEL/VOC Gas Selection 

Enable / Disable Sensor 

Change Dilution Ratio 

Change PID Lamp (10.6 or 11.7) 

If not all of the above menus appear in Programming, go to “Change Monitor Setup” and 

change the User Mode to Program. Use Mode to step out of Programming and then 

return by pressing and holding the Mode and N/- keys. 

7

Once in Diagnostic Mode, Version 2.00 and above will allow switching between 

diagnostic and standard modes by pressing and holding both the [Y] and [MODE] keys. 

V. Diagnostic and Service Test Procedures: 

1.0 Power supply / Battery / Charger 

1.1 Battery Voltage Test: 

1.1.1 Turn off the power to the MultiRAE. Open the instrument cover by removing the 2 

flat head screws from the backside (see Figure 1). 

Figure 1 

8

1.1.2 Carefully remove the battery pack or alkaline battery adapter from the unit. Make 

sure that the battery or adapter is plugged into the jack. 

1.1.3 Unplug the battery from the battery jack connected to the PC board of the 

MultiRAE. Visually inspect the wires between the battery pack or adapter and the 

connector, and between the jack and the PC board, for signs of broken or frayed wires or 

loose connector pins. 

1.1.4 Use a voltmeter to measure the voltage between the 2 outside pins of the connector 

on the battery pack. Be careful to avoid shorting the two pins as this could blow the 

internal fuse and/or damage the batteries. If the voltage is less than 4.2V the unit will not 

turn on. If using alkaline (AAA) cells, replace them with fresh cells when the voltage is 

less than 4.4V. When the voltage is below 4.4V, charge the batteries, either in the unit or 

on the external charger (RAE part number 008-3027). After replacing or recharging the 

batteries, check the voltage again. Fresh alkaline batteries should read over 6V. Fully 

charged Li-Ion or Ni-Cad batteries should read over 4.8V. 

1.1.5 If the voltage reads 0, then the internal fuse is blown or there is a broken wire. 

Replace the battery pack or adapter. 

1.3 Battery loading 

1.3.1 Remove the battery from the unit. Set the DC power supply to 4.8V DC. Connect 

the negative output to pin 1 (black wire) of the spare battery connector. Connect the 

positive power supply output to the positive side of a current meter. Connect the negative 

side of the current meter to pin 3 (red wire) of the battery connector (see figure 2). 

DC POWER 

SUPPLY 

+ 

- 

+ - 

DC 

CURRENT 

METER 

3 

1 

Figure 2 

1.3.2 Plug the connector into the mating connector in the MultiRAE. Current should be 

about 3 ma with the unit off. Turn on the unit and wait for it to complete the start up 

tests. The current will depend on the configuration of the MultiRAE: 

Basic unit: 

20 mA 

9

PID current: 

Pump current: 

LEL sensor: 

Other sensors: 

20 mA 

20 mA 

60 mA 

2-5 mA 

1.3.3 If the current exceeds the limits in the table above, then isolate the source of the 

excess consumption by removing components one at a time. CAUTION: turn off the 

power supply before removing sensors or lamps. The pump current can be checked by 

stalling the pump and observing the change in current. 

1.3.4 Replace the component found to consume excess current. If the cause of the excess 

current consumption cannot be isolated, then the unit must be returned to the factory or 

an authorized service center. 

1.4 Battery voltage Measurement Circuit 

1.4.1 Follow the steps in 1.3.1 (the current meter is not necessary). 

1.4.2 Turn on the power supply. Turn on the MultiRAE. Press [MODE] to get to the 

battery voltage display. The display should read 4.8V 

1.4.3 Increase the voltage to 6V. The display should read 6V. 

1.4.4 Slowly decrease the power supply voltage. At 4.4V the display should begin 

flashing “Bat”. At 4.2V the unit should turn off. 

1.4.5 If any of these tests fail, the unit should be returned to the factory for repairs. 

1.5 Battery Condition Tests (use for NiCd battery packs only) 

1.5.1 Charge the batteries for 8 hours, either in the MultiRAE or in an external charger 

(P/N 008-3027). 

1.5.2 Measure the voltage across pins 1 and 3 of the battery connector (test procedure 

1.1.4). If the voltage is 4.2V, then the battery is good and no further testing is needed. If the voltage 

is

Battery capacity Discharge time 

900 maH 3 hours 



Table 1.1 Battery discharge times 

1.5.4 Recharge the battery for 8 hours. Or place the battery in the external charger and 

activate the automatic discharging function before charging. (Discharging batteries 

should only be done with the NiCd battery pack, PN 500-0039-000) Repeat paragraphs 

1.5.2 

1.5.3 If the battery fails again, it must be replaced. 

1.5A Battery Condition Test without volt meter 

1.5.1A Charge batteries completely inside unit charge light turn green. Unplug charging 

adapter and turn monitor on in diagnostic mode. Allow unit to run down and turn off due 

to drained battery. Recharge battery and turn unit on in diagnostic mode. Press [MODE] 

repeatedly until you reach Run Time screen. If run time is less than 8 hours with a NiCd, 

or less than 12 hours with a Li-Ion battery, than replace the battery. 

1.6 AC Adapter Output Test 

1.6.1 Plug the 12VDC adapter into an appropriate AC source. Measure the voltage at the 

DC connector. The inside contact is positive. If the output is not at least 10V, then the 

adapter is defective and must be replaced. 

1.6.2 Inspect the DC connector. Make sure that the pin is at least 11 mm long and is not 

corroded or otherwise contaminated. Plug the AC adapter into the MultiRAE and into an 

AC outlet. With the battery removed from the unit, measure the voltage between pins 1 

and 2 of the connector in the MultiRAE. If the measured voltage is less than the voltage 

measured in paragraph 1.6.1, then there is a loose or broken wire or a poor contact. Trace 

the circuit from the external connector to the PC board to the battery connector to 

determine the cause. 

1.7 Battery Charging 

1.7.1 Remove the cover from the MultiRAE. Make sure there is a Ni-Cad battery pack 

(white) or Li-Ion battery pack (black or yellow) in the unit and that the battery connector 

is plugged in to the mating connector. The unit will not charge or operate from the AC 

adapter if the alkaline battery adapter (black) is installed. 

11

1.7.2 Perform the Battery Condition Test if the battery is a NiCd (Section 1.5), using the 

MultiRAE to charge the batteries. If the batteries fail, perform the AC Adapter Output 

Test (section 1.6.2). If the adapter output is less than 10V, then replace the adapter. If 

the adapter output is good, then replace the battery pack. 

1.8 Ambient Temperature 

1.8.1 Press the [MODE] key 7 times from the main display to show the date, time, and 

temperature. The temperature sensor is mounted on the digital PC board. 

1.8.2 Compare the displayed temperature to the actual room temperature. If either 

temperature is >40 °C the batteries may not charge properly. Charging Ni-Cad 

batteries at temperatures above 40°C may permanently damage the batteries. 

1.8.3 With the unit off and charging (red LED on), compare the ambient temperature to 

the temperature displayed in the unit. If the temperature displayed in the unit is more 

than 20°C warmer that ambient temperature, then the batteries are overheating during 

charging and should be replaced. 

1.8.4 If the temperature is colder than 10°C the batteries will not be charged to full 

capacity. 

1.8.5 If there is a large difference between the room temperature and the displayed 

temperature, but the unit and batteries do not feel warmer or colder than the room, then 

the temperature sensor or electronics need repair. 

2.0 Sensor and Measurement Tests 

2.1 Flow Related Problems (pump versions only) 

2.1.1 Check the external filter and connectors for dirt, obstructions, or leaks. If the 

external filter is wet it will block the flow of air and gas. If the external filter is 

contaminated, do not attempt to clean it. It must be replaced. 

2.1.2 Remove the cover to the MultiRAE and remove the gas piping plate. Check the gas 

piping plate and gasket for obstructions or leaks. Check for the presence of a carbon 

impregnated foam filter in the gas piping plate. This filter should only be installed over 

the CO filter. Remove and discard any carbon filters installed over any other sensors. 

When installed over the CO filter, this filter screens the CO sensor from VOCs which 

may affect the CO sensor. This filter should be replaced frequently. If the MultiRAE 

otherwise works fine, but you are unable to get a stable of accurate VOC calibration, then 

remove the carbon disk filter. 

12

2.1.3 Check the tubing between the inlet port and the pump for kinks, obstructions, or 

leaks. Check that the pump outlet port is not loose, broken, or leaking. 

2.1.4 Make sure there are no empty sensor positions. There must be either a sensor or a 

dummy sensor block in all five sensor positions (pump models). 

2.1.5 Re-install the gas piping plate. Observe that the connector nipple fits into the pump 

manifold (MultiRAE Plus does not have the manifold) and that the gasket fits snuggly 

against all the sensors. 

Figure 3 Sensor Positions 

Note: MultiRAE Plus has pump mounted to gas plate. 

2.2 Pump problems 

13

2.2.1 With the pump on, connect a flow meter to the MultiRAE inlet connector. The 

minimum acceptable flow rate is 200 ml/min. on the high speed and 150 ml/min. on the 

low speed. Rev C. boards only have one speed (high). If the flow is too low, check for 

obstructions and leaks as in section 2.1. 

2.2.2 If there are no obstructions or leaks, and the pump volume is still low, check the 

voltage at the pump power terminals. It should be 3.5V. If the input voltage is correct, 

then the pump should be rebuilt or replaced (P/N 008-3043-002). Replacement 

diaphragms are available through RAE Systems (P/N 081-0007-000). 

2.3 Sensor missing or not identified 

2.3.1 Always check the Programming Mode to verify that all sensors are enabled. Enter 

the programming menu ([N] and [MODE] together). Press [N] 4 times, or until the 

display reads “Change Sensor Configuration” Answer “Y”. The second option under 

the “Change Sensor Configuration” menu is to Enable/Disable Sensors. When this 

option is selected the display shows all installed sensors with a “*” next to the sensors 

which are enabled. Use the [MODE] key to scroll the cursor through the sensors. [Y] 

Enables sensors and [N] disables sensors. Hold the [MODE] key down until the display 

shows “save” to exit from this function. When a sensor is disabled the instantaneous 

display screen will be blank in that sensor location. The “Display Sensor Location” 

screen (press [MODE] once from the instantaneous screen) shows “---“ in the sensor 

positions which have been disabled. 

2.3.2 Verify the sensor configuration: The MultiRAE sensors have sensor type and 

expiration date stored internally. During the power-on tests the unit identifies all 

installed sensors and compares this to the configuration list. Make a note of which 

sensors the unit does identify by pressing [MODE] once from the instantaneous display. 

Turn off the unit. Remove the top cover. Disconnect the battery. Failure to disconnect 

the battery before removing or installing sensors could blow the battery pack 

internal fuse. Remove the gas piping plate. Verify the identity of each installed sensor. 

Remove, inspect, and re-insert each sensor making sure each is fully seated in its socket. 

Be sure that the shorting pin is no longer across the bottom of the sensor. The tops of the 

sensors should all be at nearly the same height. Pay particular attention to any sensors 

which were not identified. If pins are missing or the sensor or circuit board shows signs 

of damage do not re-insert the sensor: it must be replaced. 

2.3.3 Re-connect the battery and turn on power. “Configuration changed” may appear 

now even if all the sensors are working. Note which sensors are identified when the unit 

warms up and if all the installed sensors are now identified, then turn off power and reassemble 

the unit. A full calibration must be performed before using the unit, as 

calibration data may have been lost. Sensors which require a bias (NO and NH 3 ) must be 

installed, unit turned on and running, for 24 hours before stable readings can be obtained. 

14

It is always good to run the unit for at least four hours after replacing any sensor. Or use 

a SensorRAE to pre-Burn-in the sensors. 

2.3.4 If the sensor configuration is still not correct, then either the sensor is bad or there is 

an electronic problem. If possible, try replacing the sensor that is not recognized with a 

known good sensor to determine if the problem is with the sensor or the unit. Note that if 

NONE of the sensors can be identified; try removing sensors one at a time. A bad 

memory chip on one sensor may prevent the monitor from reading any of the sensor IDs. 

If this fails to isolate the problem, then the problem is with the boards in the unit. 

2.4 Sensor Response Tests 

2.4.1 Verify that there are no flow obstructions, the pump is operating correctly, and the 

gas piping plate is properly installed. Turn on the unit in Diagnostic Mode (Section IV). 

After the start-up tests are complete the display will show “raw” values for all installed 

sensors, with “RAW” in the center of the lower row. Table 2.1 has the normal raw values 

for the sensors in air (fresh air value) and with the standard calibration gasses applied 

(span value). See TN-123 for most recent changes. The most important indicator of 

sensor operation is the delta value, which is the difference between the span output and 

the zero output. Response Time is the average time required for a sensor to reach 90% 

output. 

SENSOR FRESH 

AIR 

SPAN RANGE DELTA SPAN GAS RESPONSE 

TIME 

PID 310 – 450 2000 – 8500 ≥750 100 ppm 10 sec. 

Isobutylene 

LEL 310 – 1500 1300 – 2300 ≥100 2.5% Methane 15 sec 

O 2 860 – 1250 330 – 500 ≥200 99.9% N 2 15 sec 

CO 310 – 450 450 – 900 ≥50 50 ppm CO 20 sec 

H 2 S 310 – 450 600– 950 ≥50 10 ppm H 2 S 30 sec 

NO 310 – 450 420 – 750 ≥30 25 ppm NO 20 sec 

NO 2 310 – 450 400 – 1400 ≥30 5 ppm NO 2 25 sec 

SO 2 310 – 450 500 – 1700 ≥75 5 ppm SO 2 20 sec 

Cl 2 310 – 450 450 – 1200 ≥50 10 ppm Cl 2 60 sec 

NH 3 400 – 750 700 - 1300 ≥100 50 ppm NH 3 150 sec 

PH 3 310 - 450 700 - 1800 ≥50 5 ppm PH 3 60 sec 

HCN 310 - 450 400 - 500 ≥10 10 ppm HCN 60 sec 

Table 2.1 Raw Sensor Values 

15

2.4.2 Note the raw fresh air output of the sensor. Apply the span gas for this sensor and 

wait until the reading is stable to within a few counts. Note the raw “span” output of the 

sensor. Calculate the delta (span – fresh air). 

Note: Most sensors should increase when Span gas has been applied; the O2 sensor with 

Nitrogen is the only exception. If the LEL sensor drops when gas is applied, the sensor 

has been poisoned and needs to be replaced. See TN-144 for further information on 

Sensor Poisoning. 

2.4.3 Fresh air values significantly below or above the values in the chart generally 

indicate a dead sensor but could also be due to an electronic problem, especially if all the 

values are low or identical. First replace the sensor, if you get the same problem then the 

problem is most likely in the analog or digital board, and the unit must be returned to the 

factory for service. 

2.4.4 If the CO and H2S sensor RAW readings are extremely high, they could be 

temporarily poisoned due to excessive Methanol exposure. Turn the unit on in 

Diagnostic Modes and run the monitor in a clean environment, checking to make sure 

that the RAW values are dropping over time. Be sure to store the Lamp Cleaning Kit 

solution (Methanol) in a sealed container or removed from the MultiRAE kit. If it has 

been previously stored in the case, allow the case to air out for 24 hours before storing the 

monitor inside. 

2.4.5 The delta is the most significant indicator of sensor condition. Fresh air values 

slightly below the chart values are acceptable if the delta is above the minimum value. A 

low delta means that the sensor is not responding to the test gas and must be replaced. 

2.4.6 Refer to section 2.9 for further trouble shooting of the PID sensor. 

2.4.7 If the sensor takes a long time (relative to the normal response time) to reach a 

stable output, then either the sensor is bad, the sensor is not warmed up, or there is a leak 

in the gas path (pump models). 

2.5 Calibration 

2.5.1 Inaccurate or improper calibrations can cause erratic readings, especially if the unit 

is calibrated with a gas to which the unit has a low sensitivity or with a standard gas at a 

very low concentration. In normal operating mode the software checks for a minimal 

difference in sensor output between span and zero calibration data (20 to 35 A/D counts, 

depending on software revision). This check is skipped if the calibration is performed in 

Diagnostic Mode. Software revisions before 1.05 could display erratic oxygen readings 

if a span calibration had not been performed (i.e. single sensor calibration at a value other 

than 0%). Calibration without applying the span gas can result in invalid calibration data 

being stored. A common error is calibrating the oxygen sensor to 0% in air. Some 

16

sensors require time to warm up before their zero point is stable. Calibration without 

sufficient warm up could result in significant zero drift as the sensor warms up. New 

sensors should be warmed up for at least one hour before calibrating (NH 3 and NO 

sensors should be installed and the unit run for 24 hours prior to calibrating in order for 

the bias circuit to stabilize the sensors). 

2.5.2 To check the system response to calibration gasses, use the raw output values in the 

Diagnostic Mode (section IV). Apply the calibration gasses and observe that the sensor 

responds sufficiently. 

2.5.3 If the sensor is responding well to the chosen calibration gas, allow the unit to warm 

up for at least 15 minutes, still in the Diagnostic Mode. Switch from diagnostic mode to 

standard mode by pressing and holding both the [Y] and [MODE] keys. If the sensor 

zero continues to drift, then the sensor should be replaced. 

2.5.4 If the sensor zero point is stable, then, while still in Diagnostic Mode, and proceed 

to the calibration menu (hold down [N] and [MODE]. Perform a fresh air calibration 

followed by a single gas calibration for the sensor of interest. If the sensor under test is 

oxygen, then note that the default is to calibrate to 0% with 99.9% nitrogen (say [Y] to 

the 0% question) or with another gas that has no oxygen in the mixture. 

2.5.5 Check the span gas values under “Modify Span Gas” to make sure that the cylinder 

of gas you are using matches the span values of each gas. To adjust a span concentration 

use the [MODE] key to scroll, the [Y] key to enable, and the [N] key to disable. Hold 

[MODE] until “save” appears to exit from this function. 

2.5.6 If calibration fails despite a good response in paragraph 2.5.2, check the level of gas 

in the cylinder, if it is less than 250psi, use a new bottle of gas. Otherwise there is an 

electronic problem and the unit should be returned to the factory for service. 

2.5.7 If calibration is successful, then switch from diagnostic mode to standard mode by 

pressing and holding both the [Y] and [MODE] keys. Apply the test gas and observe if 

the unit is reading correctly. If it is not then it must be returned to the factory. 

2.6 Non-zero Background 

2.6.1 “Fresh air” or “zero” calibration should be done in an area known to be free of 

gasses, which would affect the sensors. Zeroing in the presence of such gasses will result 

in inaccurate readings, especially at low concentrations, or a “NEG” alarm on one or 

more of your sensors. 

2.6.2 If you are unsure of the purity of the air, or if you are seeing non-zero background 

readings after a good calibration, then use a bottle of “zero” air during the fresh air 

17

calibration. This is the only way to positively differentiate between a faulty sensor and a 

real background signal. If you obtain a good calibration with “zero” air, and then recheck 

the zero with the same bottle of “zero” air, then you can have confidence that the 

instrument is working properly and the background signal you are seeing is caused by 

something in the environment. 

2.6.3 If, after a “zero” air calibration, you do not obtain a stable zero when applying the 

“zero” air to the instrument, then the sensor does not have a stable zero point and must be 

replaced. 

2.7 Pump Stall Adjustment. 

2.7.1 The Pump alarm can occur if the pump current exceeds the stall threshold value or 

if the pump current is 0. The pump current may increase over the threshold value as the 

pump ages or if the diaphragm is stiff due to cold temperatures. It may be necessary to 

adjust the pump stall threshold when switching from low to high pump speed or when 

adding additional lengths of tubing (Rev. D boards). Pump current may also increase if 

the inlet is blocked or the vapor trap filter is clogged. Before adjusting the pump stall 

threshold, make sure the flow path is not obstructed. Do not attempt to clean a clogged 

filter: it must be replaced. 

2.7.2 Turn on the unit in Diagnostic Mode (Section IV). The pump alarm is disabled in 

Diagnostic Mode. Press the [MODE] key repeatedly until you get to the “Pump =” 

screen. The top line is the measured pump current, and the bottom line is the threshold 

value at which the pump will stall in normal operating mode. When operating properly 

the stall threshold should be 6 - 10 counts higher than the operating current (typically 20 - 

30 counts). 

2.7.3 If the pump current is 0 then check for loose or broken wires. If the wires are 

intact, check the voltage between the red and black wires. It should be 3.5V. If the 

voltage is correct, then replace the pump assembly. If the voltage is not correct, then the 

unit will have to return to the factory for repair. 

2.7.4 If the pump is operating, block the inlet with your finger and observe the change in 

pump current: 

No change or only a few counts: 

1) Pump current < stall current means there is a leak in the flow path 

between your finger and the pump intake. Check the filter assembly, the 

inlet valve, the internal tubing, the pump inlet nipple, and the pump 

diaphragm. Clean or replace any parts that are dirty or leaking 

18

2) Pump current > stall current means that the inlet is blocked. Check the 

filter assembly, the inlet valve, and the internal tubing. Clean or replace 

any parts that are dirty or leaking 

Changes, but pump current still < stall current 

Check for leaks. If none are found, then reduce the stall threshold to be less 

than the current with the inlet blocked. Use the [N/-] key to reduce the stall 

limit. 

Changes, but pump current > stall current even with inlet unblocked 

Check for obstructions. If none are found, then raise the stall threshold. 

Use the [Y/+] key to raise the stall value to a point midway between the 

open and blocked values. 

2.7.4 If the pump current exceeds 50 counts with no obstructions, then the pump 

assembly should be replaced. 

2.8 Bias Switch for Toxic 1 Sensor 

2.8.1 The NO and NH 3 sensors require a bias to operate correctly. This bias signal is 

only available in the Toxic 1 position and is set by a switch or jumper on the analog 

board. This switch, which is located under the gas piping plate immediately behind the 

front panel LEDs, must be ON for these two sensors and OFF for all other sensors. 

2.8.2 The computer checks the bias during the start up tests and compares the sensor type 

to the bias condition. It will display the “xxx installed bias error” message if the bias is 

not correct for the type of sensor installed in the Toxic 1 position. 

2.8.3 Check the type of sensor installed in the Toxic 1 position and the position of the 

bias switch. If the switch is in the proper position for the type of sensor and the error 

message still appears, and then the analog board may be bad. 

2.8.4 Verify that the sensor type displayed in the Toxic 1 position matches the sensor 

type installed. If they match, then the analog board is bad and must be replaced. If they 

do not match, then the sensor is bad (or incorrectly programmed) and must be replaced. 

2.9 PID Sensor and Lamp Tests 

2.9.1 The “Lamp” error is an indication of a problem with the lamp current. A dirty or 

contaminated sensor often causes high readings of the VOC sensor, especially when 

exposed to moisture. A weak or inoperative lamp often causes low readings or no 

19

esponse to test gas. Readings that go up to 2000 ppm and then decrease may be caused 

by saturation of the VOC sensor by gas concentrations over 2000 ppm. 

2.9.2 To test the sensor and lamp, place the unit in Diagnostic Mode (Section IV). 

2.9.3 Press the [MODE] key to reach the Lamp Failure Threshold screen. The threshold 

value is set to about 6 counts above the value obtained with no lamp in the PID. Page 8-4 

of the MultiRAE manual contains information on setting this value. 

2.9.4 If the Lamp Failure threshold is OK, press [MODE] repeatedly to get back to the 

raw data screen. Refer to the PID values in table 2.1. 

2.9.5 Zero values below the normal range, or a weak response to test gas, may indicate 

that the lamp is not illuminating sufficiently, or that the UV light is blocked by 

contamination on the lamp window. Remove the cover, gas piping plate, PID static 

shield, and PID sensor block. Remove the lamp, clean the crystal with anhydrous 

methanol, and reinstall the lamp. Turn on the unit. Caution: wear safety glasses to 

protect your eyes from UV light. Be aware that there are high voltages across the 

lamp electrodes. Check for a visible violet glow from the lamp. If there is no glow, 

then replace the lamp. 

2.9.6 Examine the sensor block for contamination, condensation, or corrosion. Soak and 

agitate the sensor in anhydrous methanol, preferably in an ultrasonic cleaner. Dry 

thoroughly. If there are still visible signs of contamination or corrosion, then replace the 

sensor. 

2.9.7 Reassemble and test the raw sensor output. If the delta value is still low try 

replacing the lamp, then the sensor. If the delta values are still low, then there is an 

electronic problem. 

3.0 Electronic Troubleshooting 

3.1 Power On Problem 

3.1.1 If the unit will not turn on, first check the battery pack, AC adapter, and fuses. If 

the alkaline battery adapter is installed, then the A/C adapter will not power the unit. 

Both the rechargeable batteries and the alkaline adapter have internal fuses, which can 

not be replaced. 

3.1.2 Try resetting the microprocessor by unplugging the battery pack. Wait a few 

minutes, and then reconnect the battery. 

20

3.1.3 If the unit will still not turn on, then either the electronics or the membrane switch is 

defective, and the unit must be returned to the factory for service. 

3.1.4 If the unit turns off before completing the warm up tests, then the battery pack is not 

charged. As soon as the LEL, pump, and VOC lamp turn on the voltage drops below the 

shut off value. This is usually an indication that the battery internal fuses are blown. If 

the battery connectors appear normal, then try replacing the battery. 

3.2 LED, Buzzer, Back light problems 

3.2.1 Test the Green battery charge indicator LED by opening the unit and removing the 

battery pack. Then plug the AC adapter into the unit. The green LED should illuminate. 

If it does not, then the indicator board must be replaced by the factory. 

3.2.2 Test the red battery-charging indicator by plugging in the A/C adapter with a Ni- 

Cd/Li-Ion battery connected to the unit. The red LED should illuminate. If not, then 

proceed as in section 3.2.1 

3.3.3 The alarm buzzer should beep once during the power on self-test. The buzzer is on 

the analog PC board, next to the VOC and TOX1 sensor positions. If the buzzer does not 

beep during power on or power off, then it must be replaced. Do not attempt to replace 

just the buzzer; the unit will need to be sent in to the factory for service. 

3.3.4 Depressing the [N] key can turn on the back light LEDs for the LCD automatically 

in low ambient light, or manually. 

3.3.5 If the back light does not come on in low ambient light (in normal mode only, in 

diagnostic mode the backlight will not turn on), check whether the unit is in auto or 

manual back light mode. This information is the last selection under the Change Monitor 

Setup sub-menu in the programming menu. If the unit is in auto mode and the lights still 

do not come on in low ambient light, then check the back light threshold in Diagnostic 

Mode (Section IV). This menu can be used to adjust the turn on threshold and to check 

operation of the light sensor. The circular window at the top right of the front instrument 

display is for the sensor. Cover the window with a finger (with the A/C adapter 

unplugged) while in the back light threshold display. The value in the display should 

change. If it does not, then the indicator board must be replaced by the factory. 

3.3.6 If the backlight is in manual mode, use the [N] key to turn it on. It will turn off 

automatically after a few seconds to conserve battery life. 

3.3.7 If the back light can not be turned on in either mode, the unit must be returned for 

service. 

21

3.3.8 If the green or red battery charge indicator LEDs are on (i.e. the A/C adapter is 

plugged in), then auto back light mode will not work. The light from the LEDs will be 

detected by the photo sensor, which will keep its output above the threshold value. 

3.3 LCD problems 

3.3.1 Faint or missing characters or bleeding characters, in the LCD screen may be 

corrected by adjusting the display contrast. Press the [Mode] key to reach the LCD 

contrast screen. Use the [+] and [-] keys to increase or decrease the contrast. 

3.3.2 In very warm environments the LCD may show bleeding around the edge of the 

characters. If this is excessive, then adjust the contrast downward. In very cold 

environments it may be necessary to increase the contrast to see all of the characters. 

3.3.3 Random or mal-formed characters in the display could also be caused by a CPU 

hang up or by a problem with the firmware. To reset the CPU, unplug the battery pack 

then reconnect the batteries. If the problem persists, then reload the firmware (Section 

4.1). 

3.3.3 If these steps do not resolve the problem, then the unit must be returned to the 

factory to have the display replaced. 

4.0 Troubleshooting Software/Programming Problems 

4.1 Reloading 

4.1.1 Odd characters on the display, failure to respond to key presses with a keypad that 

test good or erratic operation may be caused by an error in the firmware. Re-loading the 

basic operating program can solve this. The ProRAE Suite diskette includes a copy of 

the firmware or you can download the ProRAE .Suite and the MultiRAE PGM-50 

firmware from our website: www.raesystems.com. 

4.1.2 Connect the MultiRAE to the PC serial port and press Mode repeatedly until you 

reach “Communicate with PC” Press Y/+, unit will say “Monitor will pause” Press 

Y/+ key again. Unit should read “PC Comm.” 

4.1.3 Open ProRAE Suite and select Option, Load Firmware 

4.1.4 It is very important to shut down everything on your computer that could interfere 

such as the Internet, screen savers, etc. If the firmware loading process is interrupted, the 

monitor will be turned off and will not be able to turn it on. If this happens, the unit will 

need to come back to the factory for a boot load. 

22

4.1.5 Select the most recent .AO7 file that corresponds with your monitor and select 

Open 

4.1.6 After loading the firmware, turn monitor back on in diagnostic mode and return to 

PC Comm. 

4.1.7 Select Open and File on ProRAE Suite and change Files of Type to .cfg. Select the 

default configuration file that corresponds to your instrument and select Open. 

4.1.8 You can edit the configuration file by selecting Edit, Configuration 

4.1.9 After making the all changes you want, select Options, Config All. This will 

rewrite the entire configuration and finish the rewriting of the monitor. 

4.2 Display or Text Only Modes 

4.2.1 The text mode is the simplest mode of operation. The monitor will display the 

sensor name after the monitor is turned on. The user can press the [MODE] key to see 

the instantaneous gas concentration reading, battery voltage or enter the PC 

communication menu. The user can get into the calibration mode from text mode to do 

calibrations, but cannot change most of the parameters. In the display mode, the 

MultiRAE PLUS Multi-gas Monitor is able to display all the information in the text 

mode. In addition, the following information is also available by pressing the [MODE] 

key: peak, minimum, STEL, TWA, run time in hours and minutes, temperature in degree 

C, datalog mode (or enable / disable datalogging operation in manual datalog mode), 

LEL/VOC gas names, printing and communication with a PC options. The user cannot 

get into the calibration mode from display mode, so the user cannot do calibration and 

cannot change any of the parameters. The third option is “Programming” mode, which 

gives users full access to all the menus and features. 

4.2.2 Modes can be changed from the PC configuration file (datalogging units only) or 

from the “Change Monitor Set up” sub-menu under the programming menu. 

4.2.3 To exit from Text or Display modes in a datalogging unit, use the PC program 

(ProRAE-50). Select a configuration file (.CFG file), using either the default or a custom 

file. Make sure the Program mode button is selected, and send the configuration to the 

MultiRAE. 

4.2.4 The procedure to exit from Display modes in non-datalog units, or if a PC is not 

available, depends on the firmware version number. This is the number that appears on 

the LCD when the unit is first turned on. 

23

Version 1.03 and earlier: press [MODE] to get to the “Communicate with PC” 

screen. Press [Y] to get the “Monitor will pause OK” screen. Press [N]. A bug 

in the software will drop you into the programming menu. Press [MODE] until 

you get to the “Change Monitor Setup” screen. Press [Y], and then press [N] 

until you get to the “Change User Mode” screen. Press [Y], then select 

Programming Mode. Press [MODE] to exit and save changes. 

Version 1.04: requires a PC to exit from Display mode. 

Version 1.05 and later: Start the unit in Diagnostic Mode (section IV). Press [N] 

and [MODE] together to enter the programming menu. You will be required to 

enter the password to proceed. The default password is 0000. Hold the MODE 

key down after entering the password to get to the programming menus. If you do 

not know the password you will not be able to proceed (see section 4.3). Once in 

the programming menu, proceed as above for version 1.03 to change the user 

mode. After making and saving the changes, turn the unit off to exit from 

Diagnostic Mode. 

4.3 Password Protection 

4.3.1 Units may be configured with a password from the PC configuration file. There are 

3 security levels that work in conjunction with the password: 

Security level 0: 



User cannot enter programming menu at all. 

User must enter password to enter programming menu. 

No password needed to enter programming menu. 

4.3.2 To change the password from the ProRAE software you must perform a firmware 

upgrade and send the configuration file to the unit using “Config All” 

4.4 Datalogging Enable/Disable 

4.4.1 Datalogging functions may be enabled in the ProRAE Suite. Refer to section 5.13 

of the operation manual. A three-digit code, which is unique for each serial number, is 

required to enable datalogging. This code is supplied when the data logging option is 

purchased and is on file at RAE Systems. 

4.4.2 To determine if datalogging is enabled, observe the software version number which 

is the second screen displayed when the unit is turned on. If the version number ends in 

“D”, then datalogging is enabled. 

4.4.3 Individual sensors may be selected or deselected for datalogging, either from a 

configuration file and the ProRAE-50 program, or from the “Enable/Disable Datalog” 

24

function, which is the last selection in the “View or Change Datalog” sub-menu under the 

programming menu. Sensors which are enabled for datalogging have a “*” next to their 

name in this display. As usual, use the [MODE] key to scroll, the [Y] key to enable, and 

the [N] key to disable. Hold [MODE] until “save” appears to exit from this function. 

4.5 Sensor Configuration 

4.5.1 The programming menu has a sub-menu for sensor configuration. Within this 

section users may select among the list of gasses for LEL and VOC measurement. The 

MultiRAE has the capability to select up to 50 gases for calibration and up to 50 different 

gases for measurement with both the LEL and VOC sensors. The system will 

automatically correct for the relative responses of any combination. The factory defaults 

are isobutylene for both calibration and measurement on the VOC and methane for both 

functions on the LEL. You can also Enable/Disable sensors (see section 2.3), set a 

dilution ratio (for use with dilution probe), and configure for use with either the 10.6 eV 

or 11.7 eV lamp. These powerful features can lead to confusion if the user has not 

checked the configuration before calibrating and using the unit. If the unit is tested with 

a known gas and the readings are always off by a constant percentage, check both the 

calibration gas and the measurement gas selections in the programming menu. The 

calibration gas is under the “Calibrate Monitor” sub-menu (“Change LEL/VOC span 

gas”). The measurement gas is under the “Change Sensor Configuration” menu 

(Change LEL/VOC gas”). 

4.5.2 Enter the programming menu ([N] and [MODE] together). Press [N] 4 times, or 

until the display reads “Change Sensor Configuration” Answer “Y”. 

4.5.3 The first selection is to select the LEL and VOC gas. Press [Y]. The LEL gas 

selection is displayed (if there is a LEL sensor installed). Press [N] to select a different 

gas. At this point the [+] and [-] keys scroll through the gas list. Once you have found 

the desired gas, press the [MODE] key and the display will say “Save”. Press [Y] to 

save. If the display says, “Not saved”, then the security level is set to 0 and changes are 

not allowed. Once a gas is selected, you can change the correction factor. Check the 

correction factor for accuracy by looking at TN-156. The VOC gas selection is now 

displayed. Follow the same steps to select a VOC gas. Once a gas is selected, you can 

change the correction factor. Check the correction factor for accuracy by looking at TN- 

106. The default gases, Methane and Isobutylene both have correction factors of 1. 

4.5.4 “Change Lamp Type” is used when you replace the current lamp with a new type of 

lamp. The instrument does not know what type of lamp it has installed until you select 

the correct lamp. To verify which lamp is in the unit, turn off unit. Remove the cover, 

gas piping plate, PID static shield, and PID sensor block. Remove the lamp and check 

the number etched on the side. The numbers 106 means it is a 10.6 lamp and the number 

117 mean that the lamp is an 11.7. Always clean the lamp before reinstalling (see section 

25

2.9). Turn monitor on in diagnostic mode and put unit into programming. Press [N] until 

you reach “Change Sensor Configuration” press [Y]. Press [N] until you reach “change 

Lamp Type” press [Y]. If the monitor agrees with the lamp you have installed hit [Y], 

other wise press [N] until the correct lamp is displayed. Press [Y] and the unit will ask to 

save, press [Y] again to save. 

4.5.5 Unless you are using the dilution ration to extend the range of the PID or to add O2 

to an LEL stream, the dilution ration should be 1. (See TN-167 for proper use of the 

dilution fitting) 

4.6 Alarms 

4.6.1 The MultiRAE has several types of alarms, which can be distinguished by the rate 

at which the unit beeps and by the messages on the display. See section 2.5 of the 

operation manual for a full listing of alarms and messages. When a sensor output 

exceeds an alarm setting, the unit will beep at 1, 2, or 3 beeps per second, and the sensor, 

which is causing the alarm, will flash on the LCD. The newest versions of the firmware 

also flash the name of the alarm in the sensor position (High, Low, STEL, etc.). 

4.6.2 If Alarm Latching is ON then the alarm will continue to beep even after the 

condition which caused the alarm has been cleared. Press the [Y] key to clear the alarm. 

For example, testing with 100 ppm isobutylene will cause a high alarm (with the factory 

default alarm limits) on the VOC. If the alarm is latched, then the unit will continue to 

beep even after the gas is removed. Alarm latching can be set or reset from the ProRAE- 

50 program or from the “Change Monitor Setup” sub-menu in the programming menu. 

The pump alarm is always a latching alarm and must be acknowledged before it will turn 

off. 

4.6.3 An alarm at 1 beep per second with a flashing sensor symbol indicates that the 

STEL or TWA limit has been exceeded. This alarm may continue to beep even after 

removal of the gas, which caused the alarm, because of the time averaged nature of these 

alarms. Use the [MODE] key to examine the STEL and TWA value screens to determine 

if this is the reason for the alarm. The only way to clear this alarm is to turn the unit off 

and then on again. 

4.6.4 If the LEL sensor exceeds 100% LEL, the LEL sensor turns off, for safety reasons. 

The alarm will beep at 3 flashes per second and the “LEL Off” message will flash on the 

screen. The unit must be powered off to restart the LEL sensor. 

4.7 PC Communication Problems 

26

4.7.1 Serial communications is a simple and reliable method of exchanging information 

between devices. Problems can arise from failure of the PC, failure of the unit, problems 

with the cable, or operator error. A serial port tester, which is nothing more than a box 

with a male connector on one end, a female connector on the other end, and a bank of 

LEDs for each line, is an extremely valuable, yet inexpensive, tool for diagnosing serial 

communication problems. It is connected between the two devices. The LEDs show the 

status of each line at a glance. 

4.7.2 Keep a spare serial cable for testing. Cables do break from time to time. If there is 

a serial communication failure, first try a different cable, or try a known good unit with 

the cable. If the cable tests well, then try the following tests. 

4.7.3 The most common PC problems are incorrect port selection, interference by a serial 

mouse, or failure of the serial port. 

4.7.4 If the port selected is not available on the PC, then Windows will provide an error 

message. 

4.7.5 If the MultiRAE is not in “Ready” mode it will not respond to serial 

communications. Press the [MODE] key until the “Communicate with PC” window 

appears. Press [Y] Answer [Y] to “Monitor will pause OK” The display then reads 

“Ready” and the unit is waiting to communicate. If no messages are received after a 

timeout period, then the unit will remain at “Ready” but will no longer communicate. 

Press [Mode] until you reach the communications and try again. 

4.7.6 If the port is available, but it is not the one the MultiRAE is connected to, there will 

be a time out error. This will also happen if the port is the correct port but is not 

transmitting properly. The port tester can quickly identify if the port is the correct port. 

When sending a message to the MultiRAE the LED on the transmit line from the PC 

should blink. If it does not, then nothing is being sent out this port. 

4.7.7 Similarly, the port tester can show if messages are being sent from the MultiRAE. 

The receive line from the PC should blink when the MultiRAE is sending data to the PC. 

If you see the PC transmit line blink and do not see the receive line blink in response, 

then the unit is not responding. It must be returned for service. 

4.7.8 A “NAK received” message from ProRAE-50 could have several causes: 

Check the cable and connections. 

Check for proper operation of the serial port. 

Try reloading the ProRAE program, as corrupted files could also cause this error. 

Try reloading the firmware. 

If all of the above fail, the unit must be returned for service. 

27

4.8 PC Software Problems 

4.8.1 The ProRAE-50 programs works reliably with Windows 3.1, Windows 95, 

Windows 2000 and Windows XP. Some users have reported problems with Windows 

NT. 

4.8.2 The default configuration file included on the ProRAE-50/ProRAE Suite diskette is 

the factory default configuration. Refer to the operation manual for details about the use 

of the configuration file to set-up the MultiRAE. 

4.8.3 If you are able to download data, but data for a particular sensor is missing, check 

the configuration of the unit. Each sensor must be enabled for datalogging. This is 

different from the “Enable/Disable Sensor” function in section 4.5. 

4.8.4 It is generally a good idea to clear data before beginning a datalog session. This is 

done in the unit via the “View or change datalog” sub-menu from the Programming 

Menu. If data is not cleared samples taken at different times may confuse the graphing 

program, especially if some events from a later clock time precede events with an earlier 

clock time. 

4.8.4 If you download data, and you see in the message line at the bottom of the screen 

that a number of bytes have been transferred, but there are no events listed, then check 

the datalog period. Very short periods may confuse the ProRAE program, because 

datalogging is not halted when clearing memory. If a data sample is written to memory 

after clearing, but before the MultiRAE writes a new event header in memory, then the 

ProRAE program will not find the first event header and will report no events. You can 

prevent this by turning off datalogging before clearing memory, or by selecting a longer 

datalog period temporarily. ProRAE-50 releases after 2.00 will correct this problem. 

4.8.5 If you receive a “…datalog.raw” error message, no data has been stored in the unit. 

Verify that the “L” is flashing while the unit is running, or that you are running the unit 

for the entire datalog period. As you lengthen the datalog period, if the unit does not run 

for that entire time period, no data will be stored. 

4.8.6 If you are able to download data, but your readings are very high, the instrument 

was turned on in Diagnostic mode and saved the RAW readings of the sensors. The unit 

must be turned on in normal operations, for correct readings. 

28

QUICK REFERENCE GUIDE 

MULTIRAE CALIBRATION WITH 4 CALIBRATION GAS MIX 

1. Turn on MultiRAE in a safe, clean air environment. Let unit warm up for 5 minutes. 

2. Press [N/-] and [MODE] together for 5 seconds. Display shows “Calibrate Monitor” 

3. Press [Y/+]. Display shows “Fresh Air Calibration” 

4. Press [Y/+]. Display shows results for each sensor followed by “Multiple sensor calibration” 

5. Press [Y/+]. Display names sensors selected for span calibration. All others show as “----“. 

6. Apply the gas mixture (RAE P/N 600-0050) to the filter fitting (pump models) or the calibration adapter 

(diffusion models). 

7. Press [Y/+]. Unit displays “Apply mixed gas now…40” and counts down for 40 seconds. The unit then shows 

results. After a short pause the unit displays “Calibration done! Turn off the gas” followed by “Single sensor 

calibration” 

8. Turn off the gas and disconnect the bottle. Press [MODE] twice to return to the main display, or press [Y/+] 

for VOC sensor calibration. 

9. The sensor names are displayed. Push [MODE] until VOC is selected (flashing character). 

10. Turn on the isobutylene gas and apply the gas to the unit. 

11. Press [Y/+]. Display shows “Apply VOC gas” followed by “Calibration in progress…40”. Unit counts down 

40 seconds then shows “VOC cal’ed. Reading=xxx”, where “xxx” is the calibration result. 

12. Turn off the gas and disconnect from the MultiRAE. Push [MODE] twice to return to the main display. 

MULTIRAE BUMP TEST PROCEDURE 

1. Turn on MultiRAE in a safe, well-ventilated, clean air environment. Let unit warm up for 5 minutes. 

2. O 2 should read 20.9%. All other sensors should read 0. If readings are not correct, perform a fresh air 

calibration. (See above) 

3. If unit zeros correctly, turn on the quick check four gas mix (RAE P/N 600-0060) and apply it to the filter fitting 

(pump models) or calibration adapter (diffusion models). 

4. After 40 seconds the unit should read as follows: 

CO 90 - 110 ppm 

H 2 S 45 - 55 ppm 

LEL 45 - 55% 

O 2 14 - 16% 

5. Disconnect the gas and turn off the valve. 

6. Turn on the 100 ppm isobutylene gas and attach it to the vapor trap or calibration adapter. 

7. After 40 seconds the VOC should read 90-110 ppm. 

8. Disconnect the gas and turn off the valve. 

9. Wait for the unit to return to VOC=0 and O 2 =20.9. 

10. If the span readings were incorrect, then recalibrate the sensors (see above). 

11. If the span readings were all within the specified limits the unit is ready to use. 

29

PGM-50 Diagnostic & Service Procedure 

PROGRAM MODE 

Instantaneous display of values 

[N] + [M] for 3 seconds: 

Security level = 0: No action 

Security level = 1: Password check 

Wrong password: Instantaneous display 

Correct password: Programming mode 

Security level = 2: Programming mode 

[N]: Toggle backlight 

[Y]: Test alarm/stop alarm 

[M] 

Display sensor positions 

[M] 

Display peak values 

[M] 

Display minimum values 

[M] 

Display STEL values 

[M] 

Display TWA values 

[M] 

Display battery voltage 

[M] 

Display clock / run time / internal temperature 

[M] 

Is unit configured for manual datalog 

Yes: Display Start/Stop datalog 

[Y]: Start or stop datalog 

[M]: Go to “Display LEL gas name” 

No: Display datalog mode 

[M] 

Display LEL gas name 

[M] 

Display VOC gas name 

[M] 

Communicate with PC 

[Y]: Monitor will pause OK 

[Y]: Ready… 

[N]: Return to Instantaneous display 

[M] or [N] 

Return to Instantaneous display 

30


Firmware Releases: 

Version 3.12A 3.12 3.11D 

Date 10/14/2003 6/4/2003 5/22/2003 

Error 

"Datalog Disabled" 

display 

drive for vibration alarm to 

RF control fixed 

work in Silent Mode 

New 

RF Control Enable/Disable 

Version 3.11C 3.11B 3.11A 

Date 3/18/2003 1/13/2003 8/29/2002 

Error 

check correction factor 

of LEL 

verify Silent Mode 

higher than 6 

New 

Enable Run Silent Mode 

Version 3.11 3.10A 3.10 

Date 8/29/2002 11/7/2001 9/26/2001 

Error fix LEL sensor linearity fix Power-On Zero, 

Fix O2 temp 

compensation 

so Fresh Air is not required 

Verify LEL correction 

factors 

reset NH3 low alarm to 25ppm 

check LEL "OFF" alarm 

change time out for low battery 

change Lamp driver 

prompts Single Sensor 

fix first point in datalog 

Calibration after Power-on Zero 

fix alarm when sensor is 

disabled 

New 

add disable Fresh Air 

Cal 

Default User mode is Text 

Mode 

Calibration Date is updated 

during 

Remove "View Datalog" Default setting has On-line Single Sensor calibration 

add temperature units 

selection printing turned off add User ID 

"Reset Peak" moved to 

idle mode 

add wireless abilities 

add "Change Temperature 

Units" 

31


MultiRAE Service Parts 

32


Part Number Description Price (ea.) 

008-2002-005 Cover screw, PGM 50 (5) 10.00 

008-2003-005 Cover screw washer, PGM 50 (5) 5.00 

430-0070-005 Gas plate screw,4P and 5P (5) 5.00 

430-0058-005 Gas plate washer (5) 5.00 

008-2027-000 Gas inlet nipple 8.00 

008-2020-001 Washer for inlet nipple and pwr jack 2.00 

008-2009-000 Dummy sensor 5.00 

008-2017-000 PID static shield 5.00 

008-2020-001 Gas inlet power jack washer 2.00 

008-2027-000 Gas inlet fitting assembly. (nipple) 8.00 

008-3003-000 Interface cable assembly 40.00 

008-3006-005 Charcoal filter for CO (5) 9.00 

008-3006-020 Charcoal filter for CO (20) 32.00 

008-3007-000 PID sensor assembly 75.00 

008-3013-000 Calibration Adapter (Diffusion Models) 15.00 

008-3014-000 External Filter with quick connect adapter (1) 10.00 

008-3014-001 External Filter with barb fitting adapter (1) 5.00 

008-3016-000 Calibration adapter (pump) 10.00 

008-3017-000 Housing cover 25.00 

008-3018-000 Housing case (Bottom & Top) 75.00 

008-2004-000 Housing bottom 50.00 

027-2001-000 QRAE Housing Top 25.00 

027-2004-000 QRAE Housing Bottom 50.00 

008-3022-010 Water vapor traps (pack of 10) 38.00 

008-3022-100 Water vapor traps (pack of 100) 345.00 

008-3027-000 External battery charger for NiCd Batteries 85.00 

008-3029-000 I/O port rubber cover (10) 20.00 

008-3035-002 Gas piping plate, 5P, Aluminum/Teflon hybrid 42.00 

008-3036-002 Gas piping plate, 4P, Aluminum/Teflon hybrid 42.00 

008-3037-002 Gas piping plate, 4D, Aluminum/Teflon hybrid 42.00 

008-3040-000 Packing case with foam 56.00 

008-3043-002 Pump assembly 295.00 

008-3044-002 5P pump on aluminum gas plate 337.00 

008-3045-002 4P pump on aluminum gas plate 337.00 

008-4011-000 Service Manual, PGM 50 50.00 

050-0010-000 10.6 eV, ¼” lamp 195.00 

050-0011-001 11.7 eV, ¼” lamp in ampoule 345.00 

050-0030-000 9.8 eV, ¼” lamp 245.00 

081-0002-000 Lamp cleaning kit 28.00 

081-0007-000 Pump rebuild kit 40.00 

090-2001-000 Remote probe tubing adapter 9.50 

411-0017-024 Tygon tubing, pump connections (per foot) 5.00 

500-0039-000 1700 mAH Ni-Cad battery 155.00 

500-0037-000 Li-Ion battery pack 155.00 

008-2104-002 Membrane key panel 40.00 

027-2104-000 QRAE Membrane key panel 40.00 

008-2021-005 Stand-off, digital PCB (5) 5.00 

008-2022-005 Stand-off, analog PCB (5) 5.00 

500-0029-000 Alkaline Adapter for 4 AA 12.00 

008-1171-001 LEL Sensor Module,PGM-50 175.00 

008-1161-000 O2 Sensor Module,PGM-50 120.00 

008-1111-000 H2S Sensor Module,PGM-50 195.00 

008-1112-000 CO Sensor Module,PGM-50 195.00 

008-1113-000 SO2 Sensor Module,PGM-50 195.00 

33


008-1114-000 NO Sensor Module,PGM-50 195.00 

008-1115-000 NO2 Sensor Module,PGM-50 195.00 

008-1116-001 Cl2 Sensor Module,PGM-50 195.00 

008-1117-000 HCN Sensor Module,PGM-50 395.00 

008-1118-000 NH3 Sensor Module,PGM-50 395.00 

008-1119-000 PH3 Sensor Module,PGM-50 395.00 

008-1120-000 ClO2 Sensor Module,PGM-50 395.00 

008-1121-000 EtO Sensor Module,PGM-50 395.00 

34

MultiRAE - Shawcity Limited

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?