RKI Instruments 35-3001-09 - Manual (Page 20)

16 • 35-3001-09 Oxygen/Hydrogen Sulfide Sample-Draw Detector
Recommended action
1. Verify that the calibration cylinder contains an adequate supply of a fresh test sample.
2. If a demand flow regulator calibration kit is used, use a different demand flow regulator to
determine if the original one is functioning properly.
3. If necessary, set the correct flow rate with the sensor flow control valve.
4. If you cannot set the correct flow rate, check the sample line for obstructions or kinks.
5. If the calibration/response difficulties continue, replace the sensor as described later in this
section.
6. If the calibration/response difficulties continue, contact RKI Instruments, Inc. for further
instruction.
Replacing Components of the Sample-Draw Detector
This section includes procedures to replace the oxygen sensor, H
2
S sensor, H
2
S amplifier,
hydrophobic filter, and particle filter.
Replacing the Oxygen Sensor
1. Turn off the controller.
2. Turn off power to the controller.
3. Open the housing door of the sample-draw detector.
4. Loosen the two screws on the oxygen terminal strip and remove the lugs and wires from the
terminal strip.
5. Unscrew and remove the two screws that secure the sensor retaining plate, then lift the plate
and sensor out of the flow block.
There is a gasket at the bottom of the flow block. Be sure the gasket stays in place.
6. Place the replacement sensor in the oxygen flow block, then position the retaining plate on the
two standoffs.
7. Secure the retaining plate to the standoffs with the two screws you removed in step 4.
8. Guide the wires and lugs of the replacement sensor to the oxygen terminal strip and insert each
lug into the appropriate terminal. See Figure 6 on page 11 for wiring connections. Tighten the
screws on the terminal strip.
9. Close and latch the housing door.
10. Turn on power to the controller.
11. Turn on the controller.
CAUTION: Allow the replacement sensor to warm up for 5 minutes before you continue.
12. Calibrate the replacement sensor as described in “Calibration, Oxygen Sensor” on page 19.
Replacing the H
2
S Sensor
1. Turn off the controller.
2. Turn off power to the controller.
3. Open the housing door of the sample-draw detector.
4. Unscrew and remove the two screws that secure the H
2
S amplifier, 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.