Rice Lake Truck Scales User Manual
Page 25
Install Conduit, Cabling, and J-Boxes
21
Figure 8-6. Trimming Load Cell Numbers Two, Three, and Four
3. The lowest reading of the four will be your reference cell. You won’t change that cell’s signal. Instead
you’ll 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 (0 resistance) before starting. So you can’t
increase the signal from any cell—you can 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—you’ll only add larger problems for yourself 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 through 5 until all four cells on Side
1 read within 1% of each other.
7. Side 2. Move to the Side 2 of the scale. Load each cell in turn with the weight cart and record readings on
those four cells in the same way.
The cell which reads the closest to the Side 1 reference cell will be
used as your reference cell for trimming the other cells on side 2.
Figure 8-7. Trimming Load Cell Number Five
The reference cell on Side 2 should be the same as the Side 1 readings. Move the weight cart over the cell
chosen for the Side 2 reference cell. Adjust the cell’s individual pot to equal the final Side 1 readings. In the
example at left, Cell 8 has been chosen as the Side 2 reference cell
8. Reload the other Side 2 cells (5, 6, 7 in the example) in turn with the weight cart and adjust their individual
pots so their readings are equal to the Side 2 reference cell (8 in the example).
Figure 8-8. Trimming Load Cell Number Eight
9. Repeat Steps 7 through 9 if needed to get all Side 2 cells reading within 1% of each other and within 1% of
the Side 1 reference cell.
1
4
3
2
8
5
6
7
1
4
3
2
8
5
6
7
Note
1
4
3
2
8
5
6
7