RKI Instruments 65-2331RK - Manual (Page 18)

14 • 65-2331RK H
2
S Transmitter
Replacing the Amplifier
1. Turn off the controller.
2. Turn off or unplug power to the controller.
3. Remove the junction box cover.
4. Unplug the detector terminal strip and controller terminal strip from their sockets.
You may leave the wires connected to the terminal strips.
5. Unscrew and remove the screw with the flat and lock washers that secures the
amplifier to the junction box. The screw is at the bottom right of the amplifier.
6. Remove the old amplifier.
7. Place the new amplifier in the same position as the old amplifier. A foam gasket that
orients the amplifier and keeps it from rotating is installed on the bottom of the
amplifier. Make sure the amplifier is seated flat in the junction box.
8. Install the new amplifier into the junction box with the screw, lock washer, and flat
washer you removed in Step 5.
9. Install the detector and controller terminals strips into their sockets on the new
amplifier as shown in Figure 4. If controller leads or detector leads were removed
during this procedure, refer to Figure 4 for the detector and amplifier connections.
NOTE: When a transmitter is first powered up with a new amplifier, the initial output
may be either high or below zero depending on the setting of the zero pot. Be
sure to make arrangements so that this does not cause unwanted alarms.
10. Turn on or plug in power to the controller.
11. Turn on the controller and place it into normal operation.
12. Allow the transmitter to warm up for 5 minutes.
13. Calibrate the H
2
S transmitter as described in the “Calibration” on page 15.
Calibration Frequency
Although there is no particular calibration frequency that is correct for all applications, a
calibration frequency of every 3 months is adequate for most H
2
S transmitter applications.
Unless experience in a particular application dictates otherwise, RKI Instruments, Inc.
recommends a calibration frequency of every 3 months for the H
2
S transmitter.
If an application is not very demanding, for example detection in a clean, temperature
controlled environment, and calibration adjustments are minimal at calibration, then a
calibration frequency of every 6 months is adequate.
If the application is very demanding, for example if the environment is not well
controlled, then more frequent calibration than every 3 months may be necessary.