16 • 35-3010RK-01 Sample-Draw Detector
4.
If the calibration/response difficulties continue, replace the sensor as described later
in this section.
5.
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 sensors, the hydrophobic filter, and the
charcoal filter.
Replacing the Combustible Sensor
1.
Turn off incoming power.
2.
Open the housing door of the sample-draw detector.
3.
Unscrew and remove the two screws that secure the retaining plate, then lift the plate,
connector, and sensor out of the housing.
4.
Unplug the connector from the sensor.
5.
Verify that you are using the correct replacement sensor (NC-6245 is printed on the
sensor), then plug the sensor into the connector.
6.
Place the sensor in the combustible gas sensor cavity, 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 3.
8.
Turn on incoming power.
9.
Calibrate the replacement sensor as described in “Calibration, LEL Detector” on
page 18.
Replacing the Oxygen Sensor
1.
Turn off incoming power.
2.
Open the housing door of the sample-draw detector.
3.
Unscrew and remove the two screws that secure the retaining plate, then lift the plate,
connector, and sensor out of the housing.
4.
Unplug the connector from the socket that leads from the sensor.
5.
Plug the socket of the replacement sensor into the connector.
6.
Place the sensor in the oxygen sensor cavity, 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 3.
8.
Turn on incoming power.
9.
Calibrate the replacement sensor as described in “Calibration, Oxygen Detector” on
page 20.
Replacing the Carbon Monoxide Sensor
1.
Turn off incoming power.
2.
Open the housing door of the sample-draw detector.
3.
Unscrew the 5 screws that retain the preamp circuit board.
4.
Lift the preamp circuit board away from the flow block.
Be careful not to pull on the cables that connect the preamp circuit to the main circuit
board.
There is a foam gasket in the bottom of each flow cavity beneath the circuit board.
