Rice Lake SURVIVOR ATV - Manual (Page 16)

10 ATV Portable Truck Scale Assembly Instructions
4.0 Trimming and Calibration
The following section describes steps in trimming individual cells and pairs of cells, and calibration of the ATV
truck scale. See J-box instructions located in the J-box for details on trimming.
4.1 Overview and Equipment Required
Load Cell Trimming
Individual load cell signal trimming (equalizing the signal output from each load cell) must be done first along
each side of the scale so all cells on a side have equal signal output. Adjustments can be interactive, so each side
should be done at least twice.
Once that is done, load cell pairs —one from each side—are trimmed as paired sections until each sectional output
is equal. Adjustments to each section should also be done at least twice.
1 4 3 2
8 5 6 7
1st – Trim Side 1 Cells (1, 2, 3, 4)
2nd – Trim Side 2 Cells (5, 6, 7, 8)
3rd – Trim Sections
(1,8; 2,7; 3,6; 4,5)
Weight
Cart
Junction Box
Figure 4-1. Load Cell Trimming Diagram
Equipment Required
Both of these trimming operations can be done using a weight cart parked in various locations on the scale. Final
verification of equal output trimming, however, requires test weights to be placed on the deck in various locations.
4.2 Trimming Individual Cells
Connect all load cells to the summing board terminals in the J-box and connect the main interface cable from the
J-box to the indicator. Power up the indicator.
Turn all load cell potentiometers (individual and section) in the J-box clockwise so all signals are at full strength.
Refer to the J-box instruction manual for proper set-up of jumpers and dip switches prior to trimming, then proceed
to individual cell trimming.
Side 1
The first objective is to adjust individual load cells along one side of the scale for equal signal output when equal
weight is put on those cells. For convenience, that side of the scale is referred to as side 1. The trimming weight
you use is the loaded weight cart.
1. Park the cart as close as possible to side 1 being trimmed with the wheels centered over the end load cell
mount (No. 1 in Figure 4-2). Record the indicator reading. Remember that the scale is still uncalibrated, so
the indicator readings are simply raw counts rather than weight units.
1 4 3 2
8 5 6 7
Figure 4-2. Trimming Load Cell Number One
2. Move the cart directly over mount No. 2 and record that reading. Move the cart directly over mount No. 3
and record that reading. Move the cart so the wheels are centered directly over mount No. 4 (you may have
to turn the weight cart around so all wheels remain on the scale) and record the reading.