Rice Lake Ranger 1, Operation Manual

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Ranger Simulators 1, 3 and 5 Operation 5
10. Power down the digital weight indicator and disconnect the home run cable at the junction box. Connect
the home run cable to your scale simulator. Reapply power to the digital weight indicator. With your digital
volt meter set to the millivolt range, measure across the +/- signal terminals of the scale simulator, and
adjust the simulator until your volt meter value equals the Span Calibration Signal value calculated in

Step 9.
11. Perform the indicator SPAN calibration procedure (refer to the indicator manual). The load cell simulator
adjusted to the value from Step 9, is simulating the test weight load at the calibrated capacity (25,000 lb in
this example).
12. Return the indicator to the normal weigh mode. Power down the indicator, disconnect the simulator, and
reconnect the home run cable at the junction box. Reapply power to the indicator. Provided that the scale is
still empty, the indicator should read 0 lb Re-zero the scale if necessary. The scale is now calibrated.
Pre-Calibrating an Indicator Using a Simulator (Ranger 3 and 5 Only)
For this example we will pre-calibrate an indicator that will be connected to a single load cell application. The cell
capacity is 500 lbs, rated output is 2 mV/V, and the actual output on the cell’s certificate is 2.002 mV/V.
1. Calculate the units per millivolt:
Divide the load cell capacity (500) by the actual output (2.002) to get 249.7502 lbs per millivolt.
2. Calculate the actual weight expected for the 2 mV/V setting on your simulator by multiplying the value
from Step 1 (249.7502) with the mV/V setting of the simulator and get 499.5005.
3. Connect the simulator to the weight indicator and allow the indicator to warm up for 5-10 minutes.
4. Set the simulator mV/V selector switch to 0 (vernier off) and calibrate for Zero.
5. Set the simulator mV/V selector switch to the setting used in Step 2 (for this example, 2 mV/V).
6. Calibrate the span of the indicator using the actual weight expected value from Step 2 as the weight value
(WVal for most Rice Lake indicators), 499.5005 lb for this example.
7. When the indicator is connected to the actual scale, use the calibration REZERO function to account for
any deadload on the load cell.