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Chapter 7: Maintenance
65-2646XL-05-04 M2A Transmitter Operator’s Manual
Replacing Components of the CO Detector
This section includes a procedure to replace the charcoal filter, the CO plug-in sensor and the
entire detector assembly. In most cases, it is not necessary to replace the entire detector assembly.
Replacing the CO Sensor Charcoal Filter
The charcoal filter is used to scrub out interfering gases from the environment being monitored,
such as H
2
S and certain hydrocarbons. If you are experiencing unexplained upscale readings on a
CO M2A, the charcoal filter may be saturated and no longer scrubbing out interfering gases and it
may be necessary to change the charcoal filter.
1. Turn off or disconnect power to the M2A.
2. Unscrew the detector housing cap from the housing body. Make sure not to lose the cap
gasket. See Figure 2 for an illustration of the CO detector.
3. Remove the rubber retaining boot with the charcoal filter disk from the sensor.
4. Replace the charcoal filter disk in the rubber retaining boot and install the boot onto the
sensor.
5. Make sure that the cap gasket is in place and screw the detector cap back onto the housing
body.
6. Turn on or reconnect power to the M2A.
Replacing the Plug-In CO Sensor
CAUTION:
The sensor contains electrolyte which is a dilute acid. Do not disassemble the
sensor when replacing it with a new one. If sensor electrolyte comes in contact with
your skin, wash affected area thoroughly with soap and water.
1. Turn off or unplug power to the M2A.
2. Unscrew the calibration adapter/splash guard from the detector housing cap.
3. Unscrew the detector housing cap from the detector housing body. Make sure not to lose the
cap gasket.
4. Unplug and remove the CO sensor with the rubber boot and charcoal filter attached.
5. Remove the rubber boot and charcoal filter from the old sensor.
