Rice Lake SURVIVOR PT Series - Manual (Page 23)

Trimming and Calibration 19
6.0 Trimming and Calibration
6.1 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 are somewhat 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.
Figure 6-1. Load Cell Trimming Diagram
Equipment Required
Both of these trimming operations can be done using only a weight cart parked in various locations on the scale.
Final verification of equal output trimming, however, will require test weights to be placed on the deck in various
locations.
6.2 Trimming Individual Cells
1. Connect all load cells to the summing board terminals in the junction box.
2. Connect the main interface cable from the junction box to the indicator.
3. Power up the indicator.
4. Turn all load cell potentiometers (individual and section) in the junction box clockwise until a clicking
noise is heard when you continue turning. This eliminates any initial resistance so all signals are at full
strength. You’re now ready to do individual signal 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 will be referred to as Side 1. The trimming
weight you will use will be 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 drawing to below). Record the indicator reading. Remember that the scale is still
uncalibrated, so the indicator readings are simply raw counts rather than weight units.
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
1 4 3 2
8 5 6 7
Load Cell numbers
as viewed from
Digital Indicator