RH CGS-240, Руководство пользователя

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Theory of operation
CGS-240 Manual 6/15/2021
Page 7 of 148
where e is the saturation vapor pressure (in Pascals) over liquid water in the pure phase
T is the temperature in Kelvin
and g
0
= – 2.8365744·10
3
g
1
= – 6.028076559·10
3
g
2
= 1.954263612·10
1
g
3
= – 2.737830188·10
-2
g
4
= 1.6261698·10
– 5
g
5
= 7.0229056·10
– 10
g
6
= – 1.8680009·10
– 13
g
7
= 2.7150305
2.3.2 SATURATION VAPOR PRESSURE OVE R ICE
Saturation vapor pressure over ice at a given ITS-90 temperature in the range – 100 °C to 0.01 °C is defined by the
formula








+ =
−
=

T k T k e
i
i
i
ln exp
5
1
4
0
(2)
where e is the saturation vapor pressure (in Pascals) over ice in the pure phase
T is the temperature in Kelvin
and k
0
= – 5.8666426·10
3
k
1
= 2.232870244·10
1
k
2
= 1.39387003·10
– 2
k
3
= – 3.4262402·10
– 5
k
4
= 2.7040955·10
– 8
k
5
= 6.7063522·10
– 1
2.3.3 ENHANCEMENT FACTOR
The “effective” saturation vapor pressure over water or ice in the presence of other gases differs from the ideal
saturation vapor pressures given in Equations 1 and 2. The effective saturation vapor pressure is related to the
ideal by
é = e·ƒ (3)
where é is the “effective” saturation vapor pressure
e is the ideal saturation vapor pressure (as given in Equation 1 or 2)
and ƒ is the enhancement factor