GE Bently Nevada 1900/27 Operation And Maintenance Manual page 37

The calibration procedure for the LCD is described in the following steps:
1. Remove the case cover by placing pressure with a screwdriver, or similar
object, between the case cover and base.
2. Locate the LCD zero adjust potentiometer labeled R20. It is next to the dip
switch on the top circuit board.
3. Connect the resistors and 18 AWG wires to the transducer terminal strip
according to the circuit shown in Figure 4-1.
Figure 4-1: LCD zero calibration connections.
4. Connect the 3-conductor cable to the monitor power terminal strip and
plug the other end of the cable into the proper power source. Wait 30
seconds for the monitor to complete its power up and self test functions.
After the power up cycle has finished the green OK LED will flash indicating
that the monitor is now completely powered up and OK. To stop the
flashing push the reset button.
5. Turn the zero adjust potentiometer until the LCD display reads zero.
6. Unplug the power cable from the power source.
7. Disconnect the power cable from the power supply terminal strip.
8. Disconnect the resistors and jumper wires from the transducer terminal
strip.
9. Snap the case cover back into place over the printed circuit boards.
Section 4 - Maintenance & Troubleshooting
31