RKI Instruments 35-3001-01-03 - Manual (Page 18)

14 • 35-3001-01-03 Methane 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 Methane Sample-Draw Detector
This section includes procedures to replace the sensor, hydrophobic filter, and particle filter.
Replacing the Infrared Methane 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 four screws that secure the IR methane sensor PCB, then lift the IR
methane sensor PCB 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.
5. Unplug the sensor from the IR methane sensor PCB.
6. Verify that you are using the correct replacement sensor, then plug the sensor into the IR
methane sensor PCB.
7. Place the sensor and sensor PCB in the methane sensor cavity.
8. Secure the sensor PCB on the flow block with the four 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.
CAUTION: Allow the replacement sensor to warm up for 5 minutes before you continue.
12. Calibrate the replacement sensor as described in “Calibration” on page 16.
Replacing the Hydrophobic Filter
1. Open the housing door of the sample-draw detector.
2. Disconnect the filter from the rubber elbows on each end of the filter, then remove the filter
from the sample-draw detector.
3. Install the new filter. Be sure the side of the filter marked “INLET” is connected to the elbow
that is connected to the inlet fitting.
4. Verify that the flow rate is approximately 1.0 SCFH, then close the housing door.
Replacing the Particle Filter
1. Disconnect the tubing routed to the sampling area, if installed, from the particle filter.
2. Disconnect the particle filter from the inlet fitting’s tubing stub.