RKI Instruments 35-3010RK-04 - Manual (Page 23)

35-3010RK-04 Sample-Draw Detector • 19
1. Place the controller into its calibration program or disable external alarms.
2. Open the housing door.
3. Set a voltmeter to measure in the millivolt (mV) range. It will be used in the
calibration of the CO channel.
4. When checking the mV output of the CO channel, plug the voltmeter leads into the
test points in the AMP 1 section of the main circuit board. Plug the positive lead into
the test point labeled CAL+1; plug the negative lead into the test point labeled CAL-1.
5. Use the following formula to determine the correct test points output for the CO
calibrating sample.
Output (mV) = (calibrating sample/fullscale) X 400 + 100
For example, with a calibrating sample of 50 ppm CO and a fullscale setting of 300
ppm CO, the correct output for the CO test points is 167 mV.
167 (mV) = (50/300) X 400 +100
Setting the Zero Reading
1. Screw the regulator into the zero air cylinder.
2. Connect the calibration kit sample tubing to the regulator.
3. Connect the sample tubing from the regulator to the inlet line at or near the INLET
fitting.
4. Allow the gas to flow for 1 minute.
5. Verify a voltmeter reading of 100 mV ± 2 mV at the AMP 1 test points for the CO
channel as described in the Preparing for Calibration section above.
6. If necessary, use a small flat-blade screwdriver to adjust the zero pot for the CO
channel until the voltmeter reading is 100 mV ± 2 mV.
7. Disconnect the sample tubing from the inlet line.
8. Unscrew the regulator from the zero air cylinder. Leave the sample tubing connected
to the regulator.
Setting the Response Reading
1. Screw the regulator into the 3-gas calibration cylinder.
2. Connect the sample tubing from the regulator to the inlet line at or near the sample
draw detector’s INLET fitting.
3. Allow the calibration gas to flow for 1 minute.
4. Check the mV output on the AMP 1 test points for CO and verify that the reading
matches the response reading (±2 mV) you determined earlier.
5. If necessary, use the AMP 1 span pot to adjust the reading to match the correct
response reading.
6. Disconnect the sample tubing from the sample draw detector’s inlet line.
7. Unscrew the regulator from the calibration cylinder.
NOTE: For convenience, leave the regulator connected to the sample tubing.
Returning to Normal Operation
1. Remove the voltmeter leads from the test points.