40
•
Chapter 7: Maintenance
65-2660XL-XX-04 M2A-XL Transmitter
NOTE:
The following procedure assumes the use of a calibration kit which includes a
calibration gas cylinder, a 100% nitrogen cylinder and a fixed flow regulator with an on/
off knob.
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).
NOTE:
While in the calibration program, if there is no switch activity for the calibration time-
out period the unit will return to normal operation. See “Viewing & Changing M2A-XL
Parameters” on page 28 for instructions to set the calibration time-out.
Non-Intrusive Calibration
If the M2A-XL is installed in a classified area and non-intrusive calibration is required, follow the
instructions below, but do not remove the junction box cover. Use the magnetic wand accessory to
actuate the magnetic switches instead of pushing the control switch buttons. To actuate a magnetic
switch and perform the same operation as pressing a control switch button, touch the magnet in
the end of the magnetic wand to the M2A-XL’s glass cover directly above the magnetic switch
you wish to actuate. Touching the glass and removing the wand is the same as pressing and
releasing a button. Touching the glass and keeping the wand in place is the same as pressing and
holding a button.
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 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
will freeze the display reading at the lowest response and the M2A-XL will continue 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 will
freeze 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.
