GE Corometrics 170 Series Service Manual page 159

Revision C
Serviceable Assemblies: Tocotransducer Calibration
13. Torque seal all potentiometers. Affix new sealing tape and re-install the
nameplate.
CAUTION
OFFSET VOLTAGES—Due to offset voltages induced by the
circuitry in the Trimline Tocotransducer, it is necessary to adjust
the change in voltage between the WEIGHT ON condition and
WEIGHT OFF condition—instead of simply adjusting the output
voltage for each condition. Adjusting the GAIN potentiometer
while monitoring the voltage at TP2 may show little or no voltage
change as the potentiometer is being adjusted. However, when the
weight is again placed on the button, the output voltage for this
condition may have changed significantly. In summary, it is
necessary to adjust the GAIN potentiometer and then recheck the
voltages during both the WEIGHT ON condition and the
WEIGHT OFF condition to determine the effectiveness of the
adjustment. As stated in step 12, the procedure is repeated until
the voltages fall into specification for both conditions.
14. Refer to "Testing a Repaired Transducer (TOCO or US)"
page 7-34.
170 Series Monitor
2000947-004
on
7-27