LI-COR LI-6400, Руководство пользователя

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Guided Tours
Tour #3: Controlling Chamber Conditions
3-24 Using the LI-6400
3
target water mole fraction (or relative humidity, or vapor pressure deficit).
This mode is useful for maintaining the leaf in constant conditions while
varying one parameter (i.e. when measuring a response curve).
Experiment #2 Maintaining a constant humidity
Continuing from Experiment #1 with wet filter paper clamped in the leaf
chamber, letÕs now do some constant humidity operations. We start in fixed
flow mode, to see what sort of humidities are achievable.
1 Set flow to 400
Press
2
,
f2
, then
400 enter
.
2 Put desiccant mid-range
Set the knob midway between scrub and bypass. ItÕs about one complete knob
turn from either extreme, but you donÕt have to look: you can
feel the mid-
point, because this is the region where the knob is the loosest.
3 Note the sample water mole fraction
The H2OS_mml value is probably about 20 mmol mol
-1
.
4 Switch to humidity control
Press f2 , then H , then 20 enter (or whatever value you had in the last step).
N) None (Pump OFF)
Humidity Control Options & Targets
H)
¨
H2O_sample (20 mmol)
R) RH_sample 50%
V) VPD ( Tleaf¡C) 1.00 kPa
F) Flow Rate 400 µmol/s
Figure 3-18. Constant H2O mode can be set by pressing
H
, or by highlighting
the H line and pressing
enter
.