LI-COR LI-6400, Manual

Page: 383 / 846

OPENÕs System Variables
Measured Variables
Using the LI-6400 14-7
The band broadening correction terms B
r
and B
s
for water vapor in the IRGA
cell, enabled by the configuration command
BndBrdCorr= <yes or no>,
are computed from
(14-11)
This formulation for the water band broadening correction is derived in Band
Broadening Correction for Water Vapor on page 14-23.
T
a
and T
b
are used for the density corrections for the same reasons described
above for water, and C
ms
and C
mr
are the CO
2
versions of W
ms
and W
mr
also
described above.
Leaf Temperature
The leaf temperature T
l
is measured with a chromel-constantan thermocouple
junction. The reference junction is the IRGA block, whose temperature ( T
b
)
is known. The thermocoupleÕs signal is amplified to become V
l
. (mV), and is
related to leaf temperature T
l
(C) by
ID: -10 (14-12)
Flow Meter
The flow meter is located in the console, and itÕs signal V
f
(mV) relates to
flow rate F (µmol s
-1
) by
ID: -7 (14-13)
The calibration factor a
f
is specified by the configuration command
CalFlow= <
a
f
>
B
r
1.0 0.0005 W
r
+ =
B
s
1.0 0.0005 W
s
+ =
T
l
T
b
V
l
100
--------- + =
F a
f
V
f
=