HD37AB1347
- 37 -
V3.0
Confirm with ENTER. The following screen will appear:
PROBE CALIBRATION
CALIBRATION CO2
CO2 850 ppm
<ESC> exit/cancel
<ENTER> confirm
The instrument display shows the measured CO
2
.
The CO
2
sensor can be calibrated:
•
at 400 ppm in clean air
•
at 0 ppm with nitrogen bottles.
The instrument can automatically detect the calibration methods used: whether 400
ppm or 0 ppm. The calibration should be performed at one point only: each new
calibration cancels the previous one.
Proceed as follows:
1.
Unscrew the hexagon slot peg on the instrument, located back on the aluminium
black disc. In the place of the peg, screw the small metal tube at the end of the
plastic tube connecting to the bottle for calibration.
2.
Let the inlet open if you want to perform a calibration at 400 ppm: For this
second calibration procedure,
ensure the instrument is really in clean air.
3.
For the calibration at 0 ppm, after connecting the CO
2
input to the small tube
from the nitrogen bottle, adjust the bottle flow meter to get a constant flow from
0.3 to 0.5 l/min.
4.
Wait about 15 minutes before continuing.
5.
Supply CO
2
for at least 2 minutes so as to stabilize the measurement.
6.
Press ENTER on the instrument. After few seconds, the new value read by the
probe will appear. Wait the two minutes necessary for calibration without
changing the working conditions.
