Kistler-Morse KM LD360s - Manual (Page 25)

Appendix B: System Calibration for the
Load Disc
Before calibrating, install a signal processor. Refer to the signal
processor 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.
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
Appendix B: System Calibration for the Load Disc
B-1