RKI Instruments 65-2331RK - Manual (Page 14)

10 • 65-2331RK H
2
S Transmitter
Maintenance
This section describes maintenance procedures. It includes preventive maintenance,
troubleshooting, and component replacement procedures.
Preventive Maintenance
This section describes a preventive maintenance schedule to ensure the optimum
performance of the H
2
S transmitter. It includes daily, monthly, and quarterly procedures.
Daily
Verify a display reading of 0 ppm H
2
S at the controller. Investigate significant changes in
the display reading.
Monthly
This procedure describes a test to verify that the H
2
S transmitter responds properly to
hydrogen sulfide. It describes the test using a calibration kit that includes a calibration
cup, calibration gas, sample tubing, and a fixed flow regulator with an on/off knob.
NOTE: Performing a response test on the H
2
S transmitter may cause alarms. Be sure to
put the controller into its calibration program or disable external alarms before
performing this test.
Preparing for the response test
1. Place the controller into its calibration program or disable external alarms.
2. Verify that the controller display reading for the channel you are testing is 0 ppm.
If the display reading is not zero, set the zero reading of the transmitter as described
in the Start Up section of this manual, then continue this procedure.
WARNING: Do not remove the detector housing cap or junction box cover while the
circuits are energized unless the area is determined to be non-hazardous.
Keep the detector housing cap and junction box cover tightly closed during
operation.
3. Unscrew and remove the junction box cover.
4. Set a voltmeter to read in the millivolt (mV) range.
5. Plug the voltmeter leads into the test points on the amplifier. Plug the positive lead
into the red (+) test point; plug the negative lead into the black (-) test point.
6. Use the following formula to determine the correct test points output for the test
sample.
Output (mV) = (calibrating sample/fullscale) X 400 + 100
For example, with a test sample of 25 PPM H
2
S and a fullscale setting of
100 PPM, the correct output is 200 mV.
200 (mV) = (25/100) X 400 +100
7. Screw the regulator into the calibration cylinder.
8. Use the sample tubing to connect the regulator to the calibration cup.