65-2643-05SS-4S M2A Transmitter Operator’s Manual
37
5. Turn the regulator knob clockwise to close it.
6. Unscrew the calibration gas cylinder from the fixed flow regulator. The M2A will continue to display the
minimum gas response on the display and retain the response level in its memory.
7. Adjust the oxygen reading up or down to match the 100% nitrogen cylinder oxygen concentration of
0% by using the UP/YES and DOWN/NO buttons.
NOTE:
The detector must be calibrated with 0 - 18% O
2
.
8. The M2A will perform a zero operation. The display will indicate
ZERO Gas PASS
for a few seconds, then
indicate
ZERO Gas SAVED
before indicating
Leaving CAL Mode
for a few seconds.
NOTE:
If the zero adjustment fails, see “Troubleshooting” on page 32 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 17.4 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 Oxygen Detector
This section includes a procedure to replace the oxygen plug-in sensor and the entire detector assembly. In most
cases, it is not necessary to replace the entire detector assembly.
Replacing the Plug-In Oxygen Sensor
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 oxygen sensor.
5. Carefully plug the replacement sensor into the two-socket pattern that is located in the detector housing.
6. Make sure the cap gasket is in place and screw the detector housing cap back onto the detector housing body.
7. Screw the calibration adapter/splash guard back onto the detector housing cap.
8. Turn on or plug in power to the M2A.
CAUTION:
Allow the replacement sensor to warm up for 5 minutes
before you continue with the next step.
9. Calibrate the transmitter as described in the “Calibration” on page 35.
