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65-2641RK-03 M2A Transmitter Operator’s Manual
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. between 10% LEL and 100% LEL).
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 33 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’s flexible tubing from the regulator.
NOTE:
Do not disconnect the flexible tubing from the calibration adapter.
11. Store the components of the calibration kit in a safe place.
Replacing the Hydrogen Detector
1. Turn off or disconnect power to the M2A.
2. Remove the detector junction box cover.
3. Unscrew the calibration adapter from the detector.
4. Disconnect the detector leads from the terminal block in the detector junction box. Note the position of the
color-coded leads as you remove them.
5. Unscrew the detector from the detector junction box.
6. Guide the detector leads of the replacement detector through the bottom conduit hub of the detector junction
box, then screw the mounting threads of the detector into the conduit hub. If necessary for environmental
conditions, apply thread sealant or Teflon tape to the hub and/or detector threads to seal them.
7. Connect the detector leads to the terminal block the same way the old detector was wired (see
8. Screw the calibration adapter onto the new detector.
9. Reinstall the detector junction box cover.
