Kistler-Morse KM LD3xi Load Cell - Manual (Page 29)

Appendix B. System Calibration
B-1
Appendix B: System Calibration for the
Load Disc
Before calibrating, install a signal processor. Refer to the signal proces-
sor manual for the procedures to input calibration parameters.
There are two calibration methods:
•
Live Load calibration — set lo span and hi span while moving
material into or out of the vessel. This is the preferred method.
• Manual calibration — set scale factor counts, scale factor weight,
and zero calibration value without moving material.
For use with Trim Box, refer to Trim Box Mounting and Wiring on page
3-10.
Live Load calibration requires you to move a known quantity of material
into or out of the vessel while performing the procedure. The quantity
of material moved must be at least 25% of the vessel’s total capacity to
provide the best accuracy. Live Load calibration is also based on the
material weight currently in the vessel.
Manual calibration allows you to start using the system as soon as the
load discs, junction boxes, and signal processor are installed and wired,
even if you cannot move any (or enough) material now. Manual
calibration values are based on system parameters, including rated load,
and signal processor A/D converter sensitivity. These values are
known, can be calculated, or can be obtained from the signal processor.
Manual calibration is also based on the material weight currently in the
vessel.
Note that manual calibration does not take into account the actual
response to changes in weight. Theoretically, a change in weight results
in a proportional change in digital counts. However, the structure’s
actual response to weight and interaction with piping, catwalks, roof,
discharge chutes, etc. prevents the system from achieving theoretical
values. Manual calibration is a good start, but to obtain the highest
accuracy, perform a Live Load calibration when scheduling permits you
to move material into or out of the vessel.
Refer to the indicator manual(s) for detailed calibration instructions.
This chapter describes general procedures
for calibrating the Load Disc system.
Calibration Methods