Electronics 500-P - Manual (Page 5)

IM0053A Page 5 of 10
output of the Pre-Amp is 5.00 Vdc. The Model 500 MagnaValve is normally factory
calibrated to 0-1200 lbs/min. flow rate range.
Other flow rates may be used when special conditions prevail; however, we
recommend the standard range of 0-1200 because all production valves are pre-
calibrated to that range. An emergency request for a spare valve calibrated to the
standard range is usually handled within 24 hours. A non-standard calibration may
require one week to allow access to the calibration.
The span adjustment affects the entire range of shot flow rate and it should not be
changed unnecessarily. Once the Pre-Amp span is set correctly for full scale other flow
rates must be rechecked. Settings of15%, 25%, etc., are recommended since this is
the mid-point of each compensation range. If the individual compensation points must
be revised, adjust the appropriate trimpot or perform a complete valve re-calibration.
The following procedure describes the calibration process.
7.3 Calibration Procedure Summary
Range:
Controller full-scale range
Pre-Amp full-scale range
Span:
Controller span
Pre-Amp span
Calibrate:
Run catch and weigh test with no-compensation
Select either + or - compensation
Install compensation values at 15%,25% etc. trim
pots
Run catch and weigh test with compensation
7.4 Calibration - Procedure
7.4.1 Calibration - Procedure – Range
7.4.1.1 Calibration - Procedure - Range - Pre-Amp