Vaisala AWS330 - Manual (Page 279)

Appendix B ______________________________________________________ Calculation Formulas
VAISALA ______________________________________________________________________ 277
P
wi
(t) is calculated with the formula:
01 . 0 ) log( 6 5 4 3 2 1
0
exp ) ( 4 3 2 ⋅ 





⋅ + ⋅ + ⋅ + + ⋅ + + = t a t a t a t a t a a
t
a
t P
wi
where
a0 =
-5674.5359
a1 = 6.3925247
a2 = -9.677843E - 03
a3 = 0.00000062215701
a4 = 2.0747825E - 09
a5 = -9.484024E - 13
a6 = 4.1635019
t = Temperature [K]
Table 115 Inputs for Wet Bulb Temperature Calculation
Input Variable
Air temperature (T
A
) TAAVG1M, see Table 4 on page 22
Dewpoint temperature (T
d
) DPAVG1M, see Table 4 on page 22
Atmospheric pressure (P
A
) QFEAVG1M, see Table 5 on page 23