Section 3
Operation
3-15
Table 3-1
Reference vapor
pressure (kPa)
Vapor pressure (kPa)
computed from temperature (
°
C)
Temperature (
°
C) computed
from vapor pressure (kPa)
Temp.
(
°
C)
-40.00
-30.00
-20.00
-10.00
0.00
10.00
20.00
30.00
40.00
50.00
0.019
0.051
0.125
0.286
0.611
1.227
2.337
4.243
7.378
12.340
0.019
0.051
0.126
0.288
0.614
1.233
2.348
4.263
7.416
12.409
0.019
0.051
0.126
0.288
0.614
1.233
2.347
4.260
7.414
12.419
0.019
0.051
0.126
0.288
0.614
1.233
2.347
4.262
7.412
12.399
0.019
0.051
0.125
0.286
0.611
1.227
2.337
4.243
7.377
12.339
0.019
0.051
0.126
0.287
0.611
1.226
2.334
4.238
7.378
12.365
-39.85
-29.93
-19.97
-10.00
-0.00
10.00
20.01
30.01
40.01
49.98
-39.96
-29.98
-19.99
-10.00
-0.00
10.00
20.00
30.01
40.01
50.02
-39.88
-29.93
-19.95
-9.95
0.06
10.08
20.10
30.10
40.10
50.07
pure
water
List
moist
air
Wexler
moist
air
Buck
Eq. 3-4
moist
air
Buck
Eq. 3-10
pure
water
Lowe
Eq. 3-11
pure
water
LI-COR
Eq. 3-12
From Wexler's data using
Buck
Eq. 3-4
Buck
Eq. 3-10
LI-COR
Eq. 3-12
Buck (1981) : e(T) = 0.61365 e
{kPa}
17,502T
240.97+ T
Buck (1981) : e(T) = 0.61121 [1.00072 + 3.2 10 (P) + 5.9 10 (PT)] e
-5
-9
18.729-
T
227.3
T
T +257.87
×
×
Lowe (1977): e(T) = a0 + T (a1 + T(a2 + T(a3 + T(a4 + T(a5 + a6T)))))
a0 = 0.61078
a1 = 0.044365
a2 = 1.4289
×
10
-3
a3 = 2.6506
×
10
-5
a4 = 3.0312
×
10
-7
a5 = 2.0341
×
10
-9
a6 = 6.1368
×
10
-12
LI
COR (1990) : e(T) = 0.61083 10
7.6448T
242.62+ T
−
×
