Section 4
4-2
Calibration
■
To set the H
2
O Span
1.
Setup the LI-610 for an appropriate dew point
Subtract about 5 °C from room temperature,and use that for the target
dew point temperature. Wait until the condensor’s temperature (as
monitored on the LI-610) reaches this target. The reason for this 5
°C “buffer” is to avoid condensation in the line between the LI-610’s
condensor and the IRGA. If condensation happens, you will have
large errors.
2.
Set the flow rate
Use a flow rate of about 0.5 l min
-1
from the LI-610.
3.
Attach to the IRGA
You have two choices, as shown in Figure 4-1. We recommend
option B: splitting the flow and connecting both the reference and
sample, with Match Off. The reason for this is that you will be able
to drastically reduce the equilibrium time, waiting for the sample cell.
LI-6400
PSH-0001
PORTABLE
PHOTOSYNTHESIS SYSTEM
MODEL
SR. NO.
LI-6400
PSH-0001
PORTABLE
PHOTOSYNTHESIS SYSTEM
MODEL
SR. NO.
If you connect only to the sample port,
then Match must be ON for the air to
get to the reference analyzer as well.
If you split the flow, Match can be Off.
(By turning Match ON and Off while
watching the reference concentration,
you can see the influence of the sam-
ple cell and chamber on the air stream)
A
B
Figure 4-1. Flow from the LI-610 can be connected only to the sample port
of the LI-6400 sensor head (A), or can be split to both sample and reference
ports (B).
