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Chapter 7: Maintenance
65-2670XL-XX-07 M2A-XL Transmitter
Calibration Gas Response Memory Feature
The M2A-XL has the capability to “remember” the detector’s response to the calibration gas after
the gas is removed from the detector during the fresh air and span adjustment procedure. This
feature enables one person to perform a calibration if the detector is mounted remotely from the
M2A-XL. When zero air is applied to the M2A-XL during a fresh air adjustment, the M2A-XL
freezes the display reading at the lowest response and the M2A-XL continues to display this
reading and retain it in its memory until the fresh air adjustment procedure is completed. When
calibration gas is applied to the M2A-XL during a span adjustment, the M2A-XL freezes the
display reading at the highest response to the calibration gas. The calibration gas can then be
removed and the M2A-XL will continue to display this reading and retain it in its memory until
the span adjustment procedure is completed.
Preparing for Calibration
Materials
•
0.25 LPM
fixed flow regulator
CAUTION:
Using the 0.5 LPM regulator that is normally recommended for M2A-
XLs will result in an inaccurate calibration.
• zero air cylinder (if you suspect the presence of the target gas in the sampling
environment)
• calibration gas cylinder containing a known concentration of the target gas
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).
• If calibrating a ClO
2
detector with a Cl
2
cylinder, ensure the following is true:
10% of ClO
2
fullscale
≤
cylinder concentration X 0.4
≤
100% of ClO
2
fullscale
Calibration Kit Setup
1. Connect the calibration kit sample tubing to the calibration cup hose barb.
2. Screw the calibration cup onto the detector.
3. Connect the fixed flow regulator to the calibration cup using the sample tubing.
