65-2661RK-XX-04 M2A Transmitter Operator’s Manual
39
3. Turn the regulator knob counterclockwise to open the regulator.
4. Allow calibration gas to flow for the length of time determined in “Determining Response Time” on
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
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 - 5,000 ppm CO
2
detector must be calibrated with a CO
2
concentration
between 500 and 5,000 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 34 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 hydrophobic membrane, the plug-in IR CO
2
sensor, and the
entire CO
2
detector assembly. In most cases, it is not necessary to replace the entire detector assembly.
Replacing the Hydrophobic Membrane
1. Turn off or disconnect power to the M2A.
2. Unscrew the detector housing cap from the detector housing body.
3. Gently pry up the edge of the white hydrophobic membrane with a small flat blade screwdriver or a similar
tool.
4. Peel off the hydrophobic membrane. It may be necessary to clean off the detector housing cap face to
remove any residue left from the adhesive backed membrane.
5. Install the new membrane in the recess on the face of the detector housing cap.
6. Make sure the cap gasket is in place and screw the detector housing cap back onto the detector housing body.
7. Turn on the power to the controller.
