Rice Lake SURVIVOR OTR Steel Deck - Manual (Page 31)

Trimming and Calibration 27
1. Park the cart as close as possible to side 1 being trimmed with the wheels centered over the end load cell
mount (Number 1 in Figure 7-2). Record the indicator reading. Remember that the scale is still
uncalibrated, so the indicator readings are simply raw counts rather than weight units.
Figure 8-2. Trimming Load Cell Number One
2. Move the cart directly over mount Number 2 and record that reading. Move the cart directly over mount
Number 3 and record that reading. Move the cart so the wheels are centered directly over mount Number 4
(you may have to turn the weight cart around so all wheels remain on the scale) and record the reading
Figure 8-3. Trimming Load Cell Numbers Two, Three, and Four
3. The lowest reading of the four is the reference cell. Do not change that cell’s signal. Instead use the
individual cell potentiometers for the other three cells to reduce those signals to match your reference cell.
Remember that you turned all pots to full signal before starting, so you can not increase the signal from any
cell; only decrease signal by trimming with the pots.
4. Note that the best trim is always the least trim. If one of the four readings differs from the others by more
than 5% of the displayed counts, there is probably a mechanical problem with that load cell mount causing
the large difference. Find it and correct it before going on. Check for binding, an out-of-level or misaligned
link, or similar problems with the load cell and mount. Do not try to trim down large signal differences
with resistance pots - that only adds larger problems later because of interaction between mounts.
5. Park the loaded weight cart over one of the high-reading cells on Side 1. Turn that cell’s individual
potentiometer until the displayed reading equals your recorded reference cell reading. Repeat for the other
two high-reading cells on Side 1.
6. As adjustments are somewhat interactive, repeat the process in steps 1-5 until all four cells on Side 1 read
within .1% of each other.
7. Repeat steps 1-6 for load cells 5-8 on Side 2 of the scale.
1 4 3 2
8 5 6 7
1 4 3 2
8 5 6 7