Contherm MITRE 4150 - User Calibration Procedure:

MANUALP/4000_SERVICE_0712 July2012
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1. USER CALIBRATION PROCEDURE:
This calibration procedure adjusts the GAIN factor of the CO
2
concentration.
a. Connect the external CO
2
meter on the sampling port
and take note of the external
CO
2
meter reading. Compare
this with the cabinet display
and adjust the gain as
appropriate.
b. If the cabinet display is reading too high CO
2
concentration
compared with the external CO
2
meter, then the GAIN should be
adjusted slightly DOWN. Conversely, if the cabinet display is
reading too low CO
2
concentration compared with the external CO
2
meter, then the GAIN should be adjusted slightly UP.
c. To adjust the GAIN, press
and hold the CO
2
button until
the display momentarily
blanks, this will access the
CO
2
SET POINT mode and
the SET LED above the CO
2
%
display will be turned “ON”.
d. While the SET LED above the
CO
2
% display is “ON”, press
both UP & DOWN buttons at
the same time. The CO
2
%
display will show [CA.l] for 2-3
seconds and then show the
current CO
2
reading.
e. Use the UP and DOWN
button to adjust the value
displayed. After adjustment,
the CO
2
% display will blank for
2-3 seconds and then show
the calibration factor before
returning to normal display
mode.