Psychrometer!

Psychrometer is an application to calculate the various properties of moist air. You can easily calculate values such as dew point temperature and relative humidity. - Temperature Range:-10~50(C),14~122(F)The value can be computed: Relative humidity, Volumetric humidity, Specific humidity, Vapor pressure, Saturation vapor pressure, Dew point temperature, Enthalpy, Specific volume,Discomfort Index, Heat Index, WBGT Index, Effective Temperature (Missenard).