CO
2
Monitor 2800
Instruction 19-9220
3.0 MAINTENANCE
3.1 Battery Low
When the battery voltage falls below a predetermined level, the screens
will alternate between the following:
Low Batt
and
PPM CO2
300
300
In addition, the alarm will emit three rapid tones every 30 seconds. The
unit must be given a full charge as soon as possible. Charging time is
between 1 and 1.5 hours. Once the unit is fully recharged, it will emit a
constant beeping tone for 30 seconds and display:
CHARGING
then
CHARGED
>>>>>
3.2 Air Calibration
The unit can be calibrated, approximately, in clean outside air (assumed
to be 340 ppm CO
2
) by pressing and holding down the
f
2
button for a
minimum of 3 seconds. It is essential to ensure that the unit is in clean
air before attempting an air calibration. If this condition is not ensured,
incorrect readings will be obtained. Be careful that your breath does not
affect this air calibration procedure. A 340 ppm calibration gas cylinder
can be used (See Section 4.1 for a list of Calibration accessories).
Hold the
f
2
button down and the following sequence of displays will ap-
pear.
A i r C a I
A i r C a I
0 K
The gas display screen will reappear after the
f
2
button has been re-
leased. If the calibration was unsuccessful, or if the
f
2
button was re-
leased prematurely, then the display will show the following:
A i r C a I
Failed
4
