LI-COR LI-870, Инструкция по использованию

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.
100 1000 10000 100000
Approximate CO2 Concentration (ppm)
Bandbr
oadening Co
efficient f
or H
2O
1.5
1.4
1.3
1.2
1.1
1.0
Figure B-1. The typical relationship between
h
(
α
'
c
) and CO
2
concentration.
Note: We formulated equation B-19 with 0.64
b
w
– 0.64 instead of the simple
equivalent (0.29) because this allows band broadening corrections to be turned
off by setting
b
w
to 1. When
b
w
=1,
h
(
α
c
) = 1 everywhere. Also, to avoid com-
putational problems (underflows, overflows, and division by zero) we constrain
the argument
α
c
when computing
h
(
α
c
) to be 0.1 <
α
c
≤
z
.
α
c
- 0.1 is typically
equivalent to about 600 ppm.
Calibration Equations
The following equations describe the implementation of zero and span calibrations.
Zeroing H
2
O
When the command for zeroing water is received, the LI-870 computes the water
zero from equation B-20, where
and are averaged for 5 seconds.
B-20
Appendix B. Equations summary
B-5 Appendix B. Equations summary