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Chapter 7: Maintenance
65-2640XL-04 M2A Transmitter Operator’s Manual
Determining Response Time
Since the detector junction box is installed remotely from the M2A, the response time of the
detector will depend on the length of flexible tubing that is attached to the calibration adapter/
splash guard. To determine the response time based on the length of tubing connected:
1. Place the M2A into its calibration mode or disable external alarms.
2. Note the current gas reading displayed at the M2A.
3. Screw the regulator into the calibration cylinder. Do not use a zero air cylinder for this
operation.
4. Use the flexible tubing coming from the calibration adapter/splash guard to connect the
regulator to the calibration adapter/splash guard.
5. Turn the regulator’s on/off knob counterclockwise to open the regulator. Gas will begin to
flow. Take note of the time or start a stopwatch.
6. When you first start to notice an increase in the gas reading, note how much time passed
between starting the gas flow and noticing a reading response.
7. Turn the regulator’s on/off knob clockwise to close the regulator.
8. Unscrew the regulator from the calibration cylinder.
9. 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.
10. Add 1 minute to the length of time determined in Step 6. This is the response time for the
detector. When performing a zero adjustment or span adjustment, gas must be applied for this
length of time.
Calibration
This section describes how to calibrate the M2A transmitter. It includes procedures to prepare for
calibration, enter Calibration Mode, adjust the fresh air (zero) setting, adjust the span setting, and
return to normal operation.
WARNING: The M2A is not an active gas monitoring device during the calibration
procedure. The 4-20 mA output signal will “freeze” at 3.5 mA and all relays will
remain in their non-alarm state while the M2A is in Calibration Mode. The
output signal will not indicate current readings and the relays will not resume
operating normally until the M2A is in normal operation again.
