This appendix presents the procedures for converting measured dry and wet bulb temperatures into relative humidity expressed in percent.
Convert Dry Bulb temperature from °F to °C:
Dry, °C =[(Dry,°F) -32] /1.8
Convert Dry Bulb temperature from °C to °K:
Dry, °K = (Dry, °C) + 273.15
Repeat steps 1 and 2 to convert Wet Bulb temperature (Wet) to °K.
Compute the Saturation Pressure, assuming standard-day ambient atmosphere pressure, for the Dry Bulb temperature (DrySatPres):
DrySatPres = e19.163 - (4063.2 + 184089.0/Dry)/Dry
Repeat step 4 to compute the Saturation Pressure for the Wet Bulb temperature (WetSatPres).
Compute the Relative Humidity (RH) in percent:
RH, % = 100 × [WetSatPres/DrySatPres]