STX Signal Transmitter Installation and Operation ... - Kistler-Morse

Introduction
Appendix C. MVS-STX Calculation of Manual Calibration Parameters
Appendix C. MVS-STX
Calculation of Manual
Calibration Parameters
For manual calibration, you calculate and
directly input the scale factor weight and
counts. There are three reasons for performing
a manual calibration instead of an automatic
(live load) calibration:
1. Pre-Calibration — You just installed your
system, cannot move any material now,
and want to get started using your
system with a ‘pre-calibration.’
2. Refining the Calibration — After
calibration, you kept an accurate record
of actual material weight and indicated
material weight. You want to use this
information now to ‘refine’ the calibration.
3. Re-entering Calibration Data — You want
to re-enter data from a previous calibration
that provided better accuracy than
the current calibration.
etc. prevents the system from achieving the
theoretically expected values. Additionally,
the pre-calibration could be inaccurate if your
estimate of the current material weight is off.
When scheduling permits you to move
material into or out of the vessel, perform a
live load calibration (Auto Cal) to obtain the
highest accuracy.
Follow this procedure to obtain the MVS’s
A/D converter sensitivity (needed to calculate
the manual calibration parameters):
1. If in Auto Mode (Auto LED illuminated),
press the Auto/Man Key to put the MVS
in Manual Mode. The Auto LED turns off.
2. Use the Arrow Keys to scroll to the
desired channel.
3. Press the Menu Key to display the Main
Menu. The display shows:
MAIN MENU
Disp I/O Cal
This Appendix explains and provides examples
of the calculation of Manual
calibration parameters for items 1 and 2
above. Follow the procedures in Chapter 7,
MVS-STX Calibration Menu, to input
the parameters.
Pre-Calibration
You just installed your system, cannot move
any material now, and want to get started
using your system with a pre-calibration.
Pre-calibration values are based on system
parameters, such as sensor sensitivity, rated
load, live load stress, current live load, and
A/D converter sensitivity.
Note that a pre-calibration does not take into
account the actual structural response to
changes in load. We theoretically expect a
change in load to result in a proportional
change in digital counts, but the structure’s
actual response to load and interaction with
piping, catwalks, a roof, discharge chutes,
F1 F2 F3
4. Press the F3 Key to access the Cal
Menu. The display shows:
CALIBRATION MENU
Auto
F1 F2 F3
5. Press the F3 Key to access the Manual
Menu. The display shows:
MANUAL CAL MENU
ScfCnt
6. Press the Menu Key to access the
menu’s second page. The display shows:
MANUAL CAL MENU
F1 F2 F3
7. Press the F3 Key to access Disply. The
display looks like this:
Cnts/mV:
X
Record the Cnts/mV.
Manual
ScfWgt
F1 F2 F3
Zero_Cnt
0mV cnts
Disply
F1 F2 F3
Y
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