65-2670-XX-04 M2A Transmitter Operator’s Manual
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6. Unscrew the calibration gas cylinder from the fixed flow regulator. The M2A will continue to
display the maximum gas response on the display and retain the response level in its memory.
7. Adjust the gas reading up or down to match the calibration gas cylinder concentration by
using the UP/YES and DOWN/NO buttons, then press and release the ENTER button.
NOTE:
The detector must be calibrated with a gas concentration between 10% and 100% of the
channel’s full scale value (ie. a 0 - 500 ppm NH
3
detector must be calibrated with an NH
3
concentration between 50 ppm and 500 ppm).
8. The M2A will perform a span operation. The display will indicate
SPAN Gas PASS
for a few
seconds, then indicate
SPAN Gas SAVED
before indicating
Leaving CAL Mode
for a few
seconds.
NOTE:
If the span adjustment fails, see “Troubleshooting” on page 35 for recommended actions.
9. The display will now alternate between the normal operation screen and the message
REMOVE
CAL GAS
for 1 minute. If the calibration gas has not been removed from the detector, remove it
now to avoid unwanted alarms.
During this 1 minute period, the signal output will remain fixed at 3.5 mA and the relays will
remain in their non-alarm state to avoid unwanted alarms while the calibration gas clears from the
detector. At the end of the 1 minute period, the
REMOVE CAL GAS
message will stop appearing
and the M2A will return to normal operation.
10. Disconnect the calibration adapter/splash guard’s flexible tubing from the regulator.
NOTE:
Do not disconnect the flexible tubing from the calibration adapter/splash guard.
11. Store the components of the calibration kit in a safe place.
Replacing Components of the Detector
This section includes a procedure to replace the plug-in sensor, the hydrophobic membrane, and the
entire detector assembly. In most cases, it is not necessary to replace the entire detector assembly.
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.
