User Manual
35-3010RKA-02 Sample-Draw Detector • 23
3. Connect the sample tubing from the regulator to the inlet line at or near the INLET
fitting.
4. Allow the g as to fl ow for one minute.
5. Verify a voltmeter reading of 434 mV ± 2 mV at the test points as described in the
Preparing for Calibration section above.
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 th e 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. Reconn ect the incoming sample line.
2. Wait 1 to 2 minutes to allow the calibratio n gas to be drawn out and the reading to
stabilize.
3. Close the housing door.
4. Store t he c omponents of the calib ration kit in a safe and co nvenient place.
Calibrat io n, H
2
S Dete ct or
This section describes how to calibrate the H
2
S 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, a nd a 4-gas calibration cylind er.
Preparing for Calibration
CAUTION: This proce dure 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) rang e. It w ill be used in the
calibration of the H
2
S channel.
3. Plug the voltm eter leads into the test points in the AMP 2 section of the mai n circuit
board. Plug the positive lead into the test point labeled CAL+2; plug the negative lead
into the test point labeled CAL-2.
4. Use the following formula to determine the correct test points output for the H
2
S
calibrating sample.
Output (mV) = (calibratin g sample/fullscale) X 400 + 100
For example, with a calibrating sample of 25 ppm H
2
S and a fullscale setting of 100
ppm H
2
S, the correct output for the H
2
S test point s is 2 00 mV.
200 (mV) = (25/100) X 400 +100