65-2424RK H
2
S Transmitter • 13
•
The transmitter requires frequent calibration.
NOTE:
Under “normal” circumstances, the transmitter requires calibration once every three
months. Some applications may require a more frequent calibration schedule.
Probable causes
•
The calibration cylinder is low, out-dated, or defective.
•
The transmitter is malfunctioning.
Recommended action
1. Verify that the calibration cylinder contains an adequate supply of a fresh test sample.
2. If the calibration/response difficulties continue, replace the H
2
S sensor as described later
in this section.
3. If the calibration/response difficulties continue, contact RKI Instruments, Inc. for further
instruction.
Replacing Components of the H
2
S Transmitter
This section includes procedures to replace the H
2
S sensor, amplifier PCB, and charcoal filter.
Replacing the Sensor
1. Turn off the controller.
2. Turn off or unplug incoming power at the power source end.
3. Remove the enclosure’s cover by unscrewing the four cover screws, one at each corner.
4. Unplug the H
2
S sensor from the amplifier PCB.
5. Remove the rubber boot and sealing spacer from the old sensor and install onto the
replacement sensor.
6. Carefully plug the replacement sensor into the socket pattern on the amplifier PCB.
NOTE:
Match the sensor’s male pins with the four female sockets as you plug the sensor into
the sockets.
7. Secure the cover to the enclosure.
8. Turn on or plug in incoming power at the power source end.
9. Turn on the controller.
CAUTION:
Allow the replacement sensor to warm up for 5 minutes
before you continue with
the next step.
10. Calibrate the replacement sensor as described in the Calibration section of this manual.
