GE Bently Nevada 1900/27 Operation And Maintenance Manual page 39

Adjust the 4 to 20 mA interface according to the following steps:
1. Remove the case cover by applying pressure with a screwdriver, or
similar object, between the case cover and the base.
2. Locate the 4 to 20 mA zero and gain adjust potentiometers on the
bottom circuit board. The potentiometers are labeled R16 and R34
and are located next to the 4 to 20 mA interface connector.
3. Attach the four 3 k resistors, the short lengths of wire, and the
sinewave generator as shown in Figure 4-2.
4. Connect the external DC supply to the 4 to 20 mA interface as
shown in Figure 4-2.
5. Power up the 4 to 20 mA supply and adjust the voltage to the supply
voltage that will be used in the actual installation. If the actual
supply voltage is not known, adjust the supply to 22 Vdc.
6. Power the monitor and wait for it to complete self test. After the
power up cycle has finished, the green OK LED will flash indicating
that the monitor is now completely powered up and OK. Push the
reset button to stop the flashing.
Figure 4-2: 4 to 20 mA zero and span adjust circuit.
Section 4 - Maintenance & Troubleshooting
33