Relative humidity sensor

The relative humidity sensor is located behind the circular Teflon® screen in the same housing as the sonic transducers. The screen protects the sensor from liquid water and dust while allowing water vapor to freely pass to the sensor. The sensor measures relative humidity and temperature of the cavity, then uses those measurements to calculate vapor pressure. Vapor pressure doesn't change with temperature, but relative humidity does. Because the true air temperature (measured by the thermistor needle and corrected using wind and solar measurements) differs from the cavity temperature, the true relative humidity is computed using the true air temperature and the calculated vapor pressure.