RKI Instruments M2A User Manual
Page 48
43
M2A Transmitter Operator’s Manual
Non-Intrusive Calibration
If the M2A 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’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 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.
When zero air is applied to the M2A during a fresh air adjustment, the M2A will freeze the display
reading at the lowest response and the M2A 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 during a span adjustment, the M2A will freeze the display reading at the highest response
to the calibration gas. The calibration gas can then be removed and the M2A will continue to
display this reading and retain it in its memory until the span adjustment procedure is completed.
Adjusting the Fresh Air Reading
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.
If you want to continue with calibration, press and release the UP/YES button. The display will
indicate the target gas and CAL Mode for a few seconds before showing FreshAir Adjust?.
If you want to exit Calibration Mode, press and release the DOWN/NO button. The M2A will
indicate Leaving CAL Mode and the M2A will return to normal operation.
3.
To continue with adjusting the fresh air reading, 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.
To skip adjusting the fresh air reading, press and release the DOWN/NO button. The display
will indicate SPAN w/Cal Gas?. Skip to the next section, “Adjusting the Span Setting”.
4.
Screw the zero air cylinder into the fixed flow regulator.
5.
Turn the regulator knob counterclockwise to open the regulator.
6.
Allow zero air to flow for two minutes. If there was gas present causing a reading on the M2A,
the reading should decrease and stabilize after two minutes.
7.
Turn the regulator knob clockwise to close the regulator.
8.
Unscrew the zero air cylinder from the fixed flow regulator leaving the calibration cup on the
detector. The M2A will continue to display the minimum gas response on the display and
retain the response level in its memory.
9.
Press and release the ENTER button. The M2A will perform a fresh air adjustment and the
display will indicate SPAN w/Cal Gas?.
NOTE:
If the fresh air adjustment fails, see “Troubleshooting” on page 39 for recommended
actions.
Calib?
YES/NO