RKI Instruments 65-2615RK-05-04 - Manual (Page 21)

65-2615RK-05-04 M2 Transmitter Operator’s Manual 16
NOTE: Allow the M2’s detector to warm up for 15 minutes before you continue with
the next section, “Adjusting the Fresh Air Reading.”
Adjusting the Fresh Air Reading
When the M2 is shipped from RKI Instruments, Inc., it is factory calibrated. If a full
calibration is desired at startup, see “Calibration” on page 33.
Verify that the M2 is in a fresh air environment (environment known to be free of
combustible or toxic gas vapors and of normal oxygen content, 20.9%).
CAUTION: If you suspect the presence of hydrogen sulfide in the monitoring environment, use
the calibration kit and the zero air calibration cylinder to introduce “fresh air” to
the detector and verify an accurate fresh air setting. See the “Calibration” on
page 33 for instructions on how to use a zero air cylinder when performing a fresh
air adjustment.
Non-Intrusive Fresh Air Signal Adjustment
If the M2 is installed in a classified area and non-intrusive zero adjustment 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 over 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.
WARNING: The M2 is not an active gas monitoring device during the fresh air
adjustment 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: While in the calibration program, if there is no switch activity for the
calibration time-out period the unit will return to normal operation. The factory
set time-out is 15 minutes. If you want a different time-out period, see
“Viewing & Changing M2 Parameters” on page 23 for instructions to change
the calibration time-out.
1. While in normal operation, press and hold the UP/YES button for 5 seconds to enter
Calibration Mode. Release the button when the following screen appears.
2. Press and release the UP/YES button to continue. The display will indicate the target
gas and CAL Mode for a few seconds before showing FreshAir Adjust?.
3. Press and release the UP/YES button. ENTER will alternate with FreshAir on the top
display line and the current gas reading will be on the bottom display line.
Calib?
YES/NO