Campbell IRGASON, Руководство по эксплуатации продукта

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Eq. 8
where:
C
p
and C
v
= specific heats of moist air at constant pressure and volume,
C
pw
and C
vw
= specific heat of water vapor, and
C
pd
and C
vd
= specific heat of dry air, respectively (Fleagle and Businger, 1980).
Substitute Eq. 7 (p. 55) and Eq. 8 (p. 56) into Eq. 6 (p. 55) and ignore the higher order terms. This
yields
Eq. 9
where:
T
s
= sonic virtual temperature, and
g
d
= ratio of specific heat of dry air at constant pressure to that at constant volume (Fleagle and
Businger, 1980; Kaimal and Gaynor, 1991; Kaimal and Businger, 1963; Schotanus et al., 1983).
With Eq. 9 (p. 56), the effect of humidity, on the speed of sound, is included in the sonic virtual
temperature.
The sonic virtual temperature in degrees Celsius, is given by Eq. 10 (p. 56), where
g
d
= 1.4 and R
d
= 287.04 J·K
-1
·kg
-1
.
Eq. 10
11.2 IRGASON gas analyzer
The IRGASON gas analyzer is a non-dispersive, mid-infrared absorption analyzer. Infrared
radiation is generated in the upper arm of the analyzer head before propagating along a 15 cm
optical path. Chemical species located within the optical beam will absorb radiation at
characteristic frequencies. A mercury cadmium telluride (MCT) detector in the lower arm of the
gas analyzer measures the decrease in radiation intensity due to absorption, which can then be
related to analyte concentration using the Beer-Lambert Law:
Eq. 11
IRGASON® Integrated CO
2
/H
2
O Open-Path Gas Analyzer and 3D Sonic Anemometer 56