User guide

33 65-2615RK-05-04 M2 Transmitter Operator’s Manual
Calibration
This section describes how to calibrate the M2 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 M2 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 M2 is in Calibration
Mode. The output signal will not indicate current readings and the relays
will not resume operating normally until the M2 is in normal operation
again.
NOTE: The following procedure assumes the use of a calibration kit which includes a
calibration gas cylinder, a zero air cylinder and a fixed flow regulator with an
on/off knob.
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 M2 Parameters” on page 23 for instructions to set the
calibration time-out.
NOTE: The following procedure assumes that the target gas is present in a high
enough concentration to affect the fresh air (zero) reading. If a fresh air
environment can be verified, applying zero air to the detector is not necessary
when setting the zero reading.
Non-Intrusive Calibration
If the M2 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 M2’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 M2 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 M2. When zero air is applied to the M2 during a fresh air
adjustment, the M2 will freeze the display reading at the lowest response and the M2 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 M2 during a span
adjustment, the M2 will freeze the display reading at the highest response to the
calibration gas. The calibration gas can then be removed and the M2 will continue to
display this reading and retain it in its memory until the span adjustment procedure is
completed.