RKI Instruments 65-2435RK - Manual (Page 11)

65-2435RK CO Transmitter • 11
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
1. 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 fixed flow regulator which has no on/off knob and allows
sample to flow as soon as it is screwed into a cylinder. RKI Instruments, Inc. recommends using a
0.5 LPM (liters per minute) fixed flow regulator.
NOTE: Performing a response test on the CO 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.
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. Screw the calibration cup onto the bottom of the CO detector.
4. Use the sample tubing to connect the regulator to the calibration cup.
NOTE: Do not screw the regulator into the calibration cylinder at this time.
5. Set a voltmeter to measure in the millivolt (mV) range.
6. Remove the junction box cover, then plug the voltmeter leads into the test points on the
amplifier.
Plug the positive lead into the test point labeled TP+; plug the negative lead into the test point
labeled TP-.
7. 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