Maintenance – RKI Instruments 65-2335RK User Manual
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65-2335RK CO Transmitter • 9
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 CO transmitter. It includes daily, monthly, and quarterly procedures.
Daily
Verify a display reading of 0 PPM CO at the controller. Investigate significant changes in
the display reading.
Monthly
This procedure describes a test to verify that the CO transmitter responds properly to
carbon monoxide. 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 CO transmitter may cause alarms. Be sure to
put the controller into its calibration mode 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.
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.
3.
Unscrew and remove the junction box cover.
4.
Set a voltmeter to measure 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 (-).
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 50 PPM CO and a fullscale setting of
300 PPM, the correct output is 167 mV.
167 (mV) = (50/300) X 400 +100
7.
Screw the regulator into the calibration cylinder.
8.
Use the sample tubing to connect the regulator to the calibration cup.
Performing the response test
1.
Turn the regulator’s on/off knob counterclockwise to open the regulator. Gas will
begin to flow.
2.
Allow the gas to flow for two minutes, then verify that the reading is within ± 10% of
the response reading you determined earlier.