User manual

CO230-en-GB_v1.0 1/16
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P4.0 AUTOMATIC BASELINE CALIBRATION (ABC) ON/OFF
ABC (Automatic Baseline Calibration) is used to implement a
baseline CO
2
calibration to eliminate the zero drift of the sensor. See
the next section (Calibration) for instructions on performing the
calibration. The ABC function defaults to the ON state. To disable
this feature: press ▲/DP WB while in P3.0 mode (or MXN/AVG/▼
when in P1.0 mode) to access the P4.0 settings. Press SET to enter
P4.1. The screen will flash “en” in the lower display. To disable the
ABC function press ▲/DP WB or MXN/AVG/▼ until “dis” is
displayed on the LCD. Press SET to save the settings or CAL/ESC to
exit without saving and return to P4.0.
Calibration
CO
2
CALIBRATION
The meter is factory calibrated to a 400ppm CO
2
standard
concentration.
NOTE: The meter should be returned to Extech for calibration once
per year or whenever the accuracy of the meter is in question.
CAUTION: Do not calibrate the meter in an atmosphere of unknown
CO
2
concentration.
There are 2 options for calibration; Automatic Baseline Calibration
and Manual Calibration; see below
AUTOMATIC CO
2
BASELINE CALIBRATION (ABC)
Automatic Baseline Calibration (ABC) will calibrate the meter at the
minimum CO
2
reading detected during 7 days of continuous
monitoring. The ABC default is ON. To disable the ABC function,
please refer to the P4.0 Setup mode section above. Perform the
calibration in a well ventilated area with a CO
2
level near 400ppm.