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(4) Relative humidity
Format for entering the formula
RH (D#W)
D: Dry bulb temperature
W: Wet bulb temperature
The following formula is used for relative humidity calculation.
((B - 0.000662 × 1013.0 × (D - W)) ÷ A) × 100
A: Dry bulb saturated water vapor pressure B: Wet bulb saturated water vapor pressure
D:Dry bulb temperature
W:Wet bulb temperature
The following formula is used for the calculation of saturated water vapor pressure
6.1121 × EXP ((17.502 × T) ÷ (240.9 + T))
T:
Temperature
(5) Dew-point temperature
Format for entering the formula
DEW (T#H)
T: Temperature data channel
H: Relative humidity channel
For the input of relative humidity, use the results of the RH calculation shown above in (4), or
the output from an external thermometer, and then register the channel as Xh.
The formula below is used for the dew-point temperature.
t: Temperature
data
h:
Relative humidity data
D: Dew-point
temperature
1) K = t + 273.15
2) When t
≥
0
W = EXP(-5800.2206 / K + 1.3 K × (-0.048 K × (0.41764768E-4
- 0.14452093E-7 × K)) + 6.5459673 × LOG(K))/1000
When t < 0
W = EXP(-5674.5359 / K + 6. K × (-9.677843E-3 + K × (0.62215701E-6
+ K × (0.20747825E-8 - 9.484024E-13 × K))) + 4.1635019 ×LOG(K))/1000
3) S = W × h/100
4) P = S × 1000
5) Y = LOG(P)
6) When P
≥
611.2
D = -77.199 + Y × (13.198 + Y × (-0.63772 + 0.071098 × Y))
When P < 611.2
D = -60.662 + Y × (7.4624 + Y × (0.20594 + 0.016321 × Y))
(6) Moving average
Calculate the average of the data for past T seconds.
Format for entering the formula
AVE (X#T)
AVEH (X#T)
X: Data channel No.
T: Time series interval (sec.)
The table below shows the difference between AVE and AVEH.
AVE
AVEH
Sampling cycle
1 s
0.1 s
Range of T
1 to 3600
1 to 300
