65-2641RK-05-04 M2A Transmitter Operator’s Manual
37
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
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. Use the flexible tubing coming from the calibration adapter/splash guard to connect the regulator to the
calibration adapter.
6. Turn the regulator knob counterclockwise to open the regulator.
7. Allow zero air to flow for the length of time determined in “Determining Response Time” on page 35.
8. Turn the regulator knob clockwise to close the regulator.
9. Unscrew the zero air cylinder from the fixed flow regulator. Leave the calibration adapter/splash guard’s
flexible tubing connected to the regulator. The M2A will continue to display the minimum gas response on
the display and retain the response level in its memory.
10. 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 33 for recommended actions.
Adjusting the Span Setting
1. If you want to continue with adjusting the span setting, press and release the UP/YES button.
APPLY
will
alternate with
SPAN Gas
on the top display line and the current gas reading will be on the bottom display
line.
If you want to skip adjusting the span reading, press and release the DOWN/NO button. The display will
indicate
Leaving Cal Mode
and the M2A will return to normal operation.
2. Screw the calibration gas cylinder into the fixed flow regulator.
Calib?
YES/NO
