Vaisala HUMICAP HMT330 SERIES - MODBUS Exception Status Outputs

User's Guide ______________________________________________________________________
192 _________________________________________________________________ M210566EN-J
Enthalpy:
x
x
T
h 




 5.2)00189.001.1()15.273(
(4)
The water vapor saturation pressure P
ws
is calculated by using two
equations (5 and 6):



3
oi
i
i
TCT
(5)
where:
T
= temperature in K
C
i
= coefficients
C
0
= 0.4931358
C
1
= -0.46094296 * 10
-2
C
2
= 0.13746454 * 10
-4
C
3
= -0.12743214 * 10
-7



3
1
4
lnln
i
i
iws
bbP (6)
where:
b
i
= coefficients
b
-1
= -0.58002206 * 10
4
b
0
= 0.13914993 * 10
1
b
1
= -0.48640239 * 10
-1
b
2
= 0.41764768 * 10
-4
b
3
= -0.14452093 * 10
-7
b
4
= 6.5459673
The water vapor pressure is calculated using:
100
ws
w
P
RHP 
(7)