18 • 35-3001A-07-03 Methane/Hydrogen Sulfide Sample-Draw Detector
amplifier.
7. Place the sensor and amplifier in the H
2
S sensor cavity.
8. Secure the H
2
S amplifier on the flow block with the two screws you removed in step 4.
9. Close and latch the housing door.
10. Turn on power to the controller.
11. Turn on the controller.
12. Allow the sample-draw detector to warmup for 5 minutes.
13. Calibrate the replacement sensor as described in “Calibration, H
Replacing the H
2
S Amplifier
1. Turn off the controller.
2. Turn off power to the controller.
3. Open the housing door of the sample-draw detector.
4. Disconnect the red and blue wires coming from the H
2
S amplifier from the AMP 2 position on
the detector/amp terminal strip.
5. Unscrew the two screws in the upper right and lower left corners of the H
2
S flow block then
lift the H
2
S amplifier and sensor off of the flow block.
There is a gasket at the bottom of the flow block. Be sure the gasket stays in place.
6. Disconnect the sensor from the H
2
S amplifier.
7. Plug the H
2
S sensor into the new H
2
S amplifier.
8. Place the sensor and amplifier in the H
2
S sensor cavity.
9. Secure the H
2
S amplifier on the flow block with the two screws you removed in step 5.
10. Reconnect the wires coming from the H
2
S amplifier to the AMP 2 position on the detector/
amp terminal strip.
Connect the red wire to the “+” terminal. Connect the blue wire to the “S” terminal.
NOTE:
When the sample-draw detector is first powered up with a new amplifier, the initial
output may be either high or below zero depending on the setting of the span pot. Be sure
to make arrangements so that this does not cause unwanted alarms.
11. Turn on power to the controller.
12. Turn on the controller and place it into normal operation.
13. Allow the sample-draw detector to warmup for 5 minutes.
14. Calibrate the sample-draw detector as described in “Calibration, H
Replacing the Hydrophobic Filter
1. Turn off the controller.
2. Turn off power to the controller.
3. Open the housing door of the sample-draw detector.
4. Disconnect the filter from the rubber elbows on each end of the filter, then remove the filter
from the sample-draw detector.
