RKI Instruments 35-3001A-09 - Manual (Page 19)

35-3001A-09 Oxygen/Hydrogen Sulfide Sample-Draw Detector • 15
Preparing for the response test
NOTE: This procedure describes the RKI calibration kit that includes a demand flow regulator.
1. Verify that the display reading at the controller is 20.9% for the oxygen channel and 0 ppm for
the H
2
S channel.
If the display reading is not 20.9% for the oxygen channel or 0 ppm for the H
2
S channel, set
the zero reading as described in “Calibration, Oxygen Sensor” on page 21 or “Calibration, H
2
S
Sensor” on page 22, then continue this procedure.
2. Set a voltmeter to measure in the millivolt (mV) range.
3. Open the housing door, then plug the voltmeter leads into the test points on the H
2
S amplifier.
Plug the positive lead into the red (+) test point; plug the negative lead into the black (-) test
point.
4. 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 25 ppm and a fullscale setting of 100 ppm, the correct
output is 200 mV.
200 (mV) = (25/100) X 400 +100
Performing the response test
1. Screw the demand flow regulator into the hydrogen sulfide calibration cylinder.
2. Connect the calibration tubing from the demand flow regulator to the inlet fitting. Gas will
begin to flow.
3. After approximately one minute, verify that the millivolt output at the hydrogen sulfide
amplifier stabilizes within ± 20% of the reading determined above. If the reading is not within
± 20% of the determined value, calibrate the sample-draw detector as described in
“Calibration, H
2
S Sensor” on page 22.
NOTE: If an H
2
S cylinder with a balance of nitrogen is used, the oxygen reading should decrease
to 0% or very close to 0%. If it does, you do not need to perform the breathing test in step
7.
4. Remove the calibration tubing from the inlet fitting.
5. Store the calibration kit in a safe place.
6. Remove the voltmeter leads from the H
2
S amplifier and plug them into the oxygen amplifier.
Plug the positive lead into the red (+) test point; plug the negative lead into the black (-) test
point.
7. Exhale into the sample-draw detector’s inlet fitting.
8. Stop exhaling into the sample line, then verify that the millivolt reading decreased.
9. If the reading does not decrease, calibrate the sample draw detector as described in
“Calibration, Oxygen Sensor” on page 21.
10. Remove the voltmeter leads from the oxygen amplifier.
11. Close the housing door.