PP Systems CIRAS-3, Руководство по эксплуатации

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CIRAS-3 Operation Manual V. 1.09 163 support@ppsystems.com
Physical Constants Used in Equations
•
Volume of one kg mole of gas =0.0224 m
3
, at 1013.25 millibar barometric pressure and 273.15 °K
•
Latent heat of vaporization of water (
λ
) = 45064.3 - (T
c
x 42.9)
•
Molecular weight of air (M
a
) = 28.97
•
Specific heat at constant pressure (C
p
) = 1.012 kJ kg
-1
K
-1
•
Stefan Boltzmann constant (
σ) = 5.6704 x 10
-8
W m
-2
K
-4
Definition of Symbols
Measured Parameters
Symbol Parameter Unit
V
20
Flow rate of dry air into cuvette at STP cc sec
-1
A Projected leaf area cm
2
r
b
Boundary layer resistance to water vapor m
2
s mol
-1
P Atmospheric pressure mb
Q Photon flux density incident on cuvette µmol m
-2
s
-1
T
c
Cuvette air temperature °C
Calculated Parameters
Symbol Parameter Unit
W
Mass flow of dry air per unit leaf area mol m
-2
s
-1
e
in
Partial pressure of water vapor of air entering cuvette mb *
e
out
Partial pressure of water vapor of stirred cuvette air mb *
E Transpiration rate mmol m
-2
s
-1
e
s
Saturated vapor pressure at cuvette air temperature mb
e
leaf
Saturated vapor pressure (inside the leaf) at leaf temperature mb
T
leaf
Leaf temperature °C
Δt
Temperature difference between the air and the leaf °C
H Radiation absorbed by the leaf W m
-2
r
s
Stomatal resistance to water vapor m
2
s mol
-1
g
s
Stomatal conductance to water vapor mmol m
-2
s
-1
C
in
CO
2
concentration of air entering cuvette µmol mol
-1
*
C
out
CO
2
concentration of air inside and exiting the cuvette µmol mol
-1
*
A CO
2
Assimilation rate (net photosynthesis) µmol m
-2
s
-1
g
c
Total conductance to CO
2
transfer mmol m
-2
s
-1
C
i
CO
2
concentration of sub-stomatal cavity µmol mol
-1
* Detected by IRGAs, temperature and pressure corrected, effects of foreign gas broadening (water vapor
effects) on measurement corrected.