Section 4
Calibration
4-15
11.
Click on the CO
2
Cal tab. Enter the mole fraction in the target
entry.
12.
When stable (1-2 minutes) click
Span
. Check the value of S
c
(typically 0.9-1.1).
Span H
2
O
13.
To set the H
2
O span, flow air of known dew point through the
calibration tube at about 0.5 to 1.0 LPM. To avoid condensation,
use a dew point temperature several degrees below the ambient
temperature.
14.
Click the H
2
O tab, and note the present value of S
w
. Enter the
span gas dew point temperature in the target entry.
15.
Observe the H
2
O dew point and wait for it to stabilize. This may
take up to 15 or 20 minutes.
16.
When the reading has stabilized, click
Span
. Note the value of S
w
(typically 0.9-1.1).
