System Description
Equation Summary
Using the LI-6400
1-9
The function
e
(T) is saturation vapor pressure (kPa) at temperature
T
(C). The
formula used by the LI-6400 is (14-21) on page 14-10.
Stomatal Conductance to Water Vapor
The stomatal conductance
g
sw
to water vapor (mol H
2
O m
-2
s
-1
) is obtained
from the total conductance by removing the contribution from the boundary
layer.
(1-9)
where
k
f
is a factor based on the estimate
K
of the fraction of stomatal con-
ductances of one side of the leaf to the other (termed
stomatal ratio
through-
out this manual),
(1-10)
and
g
bw
is the boundary layer conductance to water vapor (mol H
2
O m
-2
s
-1
)
from one side of the leaf. The boundary layer conductance correction thus de-
pends on whether the leaf has stomata on one or both sides of the leaf.
Net Photosynthesis
The mass balance of CO
2
in an open system is given by
(1-11)
where
a
is assimilation rate (mol CO
2
m
-2
s
-1
),
c
i
and
c
o
are incoming and
outgoing mole fractions (mol CO
2
mol air
-1
) of carbon dioxide. Using (1-2),
we can write
(1-12)
which rearranges to
g
sw
1
1
g
tw
--------
k
f
g
bw
---------
Ð
-----------------------
=
k
f
K
2
1
+
K
1
+
(
)
2
---------------------
=
sa
u
i
c
i
u
o
c
o
Ð
=
sa
u
i
c
i
u
i
sE
+
(
)
c
o
Ð
=
Summary of Contents for LI-6400
Page 1: ...Using the LI 6400 Portable Photosynthesis System ...
Page 15: ...Part I The Basics ...
Page 16: ......
Page 174: ...Making Measurements Answers to Questions 4 56 Using the LI 6400 4 ...
Page 175: ...Part II Useful Details ...
Page 176: ......
Page 200: ...Standard Tools Power ON Hooks 5 24 Using the LI 6400 5 ...
Page 214: ...Real Time Data Real Time Graphics 6 14 Using the LI 6400 6 ...
Page 234: ...Environmental Control Light Control 7 20 Using the LI 6400 7 ...
Page 244: ...Light Sensor Considerations Gallium Arsenide Phosphide GaAsP Sensor 8 10 Using the LI 6400 8 ...
Page 288: ...Data Logging Making Your Own AutoPrograms 9 44 Using the LI 6400 9 ...
Page 289: ...Part III Working With Files ...
Page 290: ......
Page 312: ...The LPL File System Troubleshooting 10 22 Using the LI 6400 10 ...
Page 340: ...Downloading Files Using a Data Capture Program 11 28 Using the LI 6400 11 ...
Page 375: ...Part IV Configuration Issues ...
Page 376: ......
Page 420: ...Defining User Variables Old Style vs New Style 15 18 Using the LI 6400 15 ...
Page 454: ...Using an Energy Balance Further Reading 17 12 Using the LI 6400 17 ...
Page 455: ...Part V Maintenance Troubleshooting ...
Page 456: ......
Page 572: ...Troubleshooting Useful Information 20 46 Using the LI 6400 20 ...
Page 593: ...Part VI Programming ...
Page 594: ......
Page 622: ...Programming with LPL Compiler Directives 22 28 Using the LI 6400 22 ...
Page 846: ...Index I 16 Using the LI 6400 ...