Division 3.3.2.4 Dew point determination from relative humidity and dry bulb temperature

United Kingdom

If humidity is measured as a relative humidity, RH %, the dew point, T _dew, shall be determined from RH % and dry bulb temperature by means of equation (7-81):

T_{dew} = \frac{2,0798233 \times 10^{2} - 2,0156028 \times 10^{1} \times \ln (p_{H2O}) + 4,6778925 \times 10^{– 1} \times \ln {(p_{H2O})}^{2} - 9,2288067 \times 10^{– 6} \times \ln {(p_{H2O})}^{3}}{1 - 1,3319669 \times 10^{– 1} \times \ln (p_{H2O}) + 5,6577518 \times 10^{– 3} \times \ln (p_{2}^{H2O}) - 7,517286510 \times 10^{– 5} \ln (p_{3}^{H2O})}

(7-81)

Where

p _H2O

water vapor pressure scaled to the relative humidity at the location of relative humidity measurement, T _sat = T _amb

T _dew

dew point as determined from relative humidity and dry bulb temperature measurements