RKI Instruments 35-3010RKA-03 - Manual (Page 27)

35-3010RKA-03 Sample-Draw Detector • 23
6. If necessary, use a small flat-blade screwdriver to adjust the zero pot until the
voltmeter reading is 434 mV ± 2 mV.
7. Disconnect the sample tubing from the inlet line.
8. Unscrew the regulator from the zero air calibration cylinder. Leave the sample tubing
connected to the regulator.
Returning to Normal Operation
1. Reconnect the incoming sample line.
2. Wait 1 to 2 minutes to allow the calibration gas to be drawn out and the reading to
stabilize.
3. Close the housing door.
4. Store the components of the calibration kit in a safe and convenient place.
Calibration, CO Detector
This section describes how to calibrate the CO detector in the sample-draw detector. It
includes procedures to prepare for calibration, set the zero reading, set the response
reading, and return to normal operation.
NOTE: This procedure describes calibration using a demand flow regulator, a zero air
calibration cylinder, and a 3-gas calibration cylinder.
Preparing for Calibration
CAUTION: This procedure may cause alarms at the controller. Take appropriate action to avoid
this, such as entering the calibration mode at the controller.
1. Open the housing door.
2. Set a voltmeter to measure in the millivolt (mV) range.
3. 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.
4. 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.