Θ+ θ – Vaisala HMT330 User Manual
Page 198
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User's Guide _______________________________________________________________________
196 __________________________________________________________________ M210566EN-K
Mixing ratio:
w
w
P
p
P
x
-
99
.
621
×
=
(2)
Absolute humidity:
T
P
a
w
⋅
=
68
.
216
(3)
Enthalpy:
x
x
T
h
⋅
+
⋅
+
⋅
−
=
5
.
2
)
00189
.
0
01
.
1
(
)
15
.
273
(
(4)
The water vapor saturation pressure P
ws
is calculated by using two
equations (5 and 6):
∑
=
−
=
Θ
3
o
i
i
i
T
C
T
(5)
where:
T
=
temperature in K
Ci = coefficients
C0 = 0.4931358
C1 = -0.46094296 * 10-2
C2 = 0.13746454 * 10-4
C3 = -0.12743214 * 10-7
∑
−
=
Θ
+
Θ
=
3
1
4
ln
ln
i
i
i
ws
b
b
P
(6)
where:
bi = coefficients
b-1 = -0.58002206 * 104
b0 = 0.13914993 * 101
b1 = -0.48640239 * 10-1
b2 = 0.41764768 * 10-4
b3 = -0.14452093 * 10-7
b4 = 6.5459673
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