The DewTran series (patent pending) is a low cost , precision chilled mirror hygrometer that provide quick and accurate humidity, dew point, air temperature and barometric pressure measurements. Typically used for calibration chambers for 85C at 85% measurements, glove box applications that need to monitor barometric pressure, pharmaceutical, clean room, and HVAC application. The unit is very robust all exposed electronics to the process gas are parylene coated, unit measures dew point down to -40C. The unit can be configured for wall mount application and has a self-aspirating (patent pending) fan for continuous air flow, it can also be configured for remote, duct mount , flow through applications and has options for air temperature, barometric pressure, right angle mounting brackets and a flow through sample chamber. Because of its accuracy, stability and repeatability, the DewTran is used as a reference standard to calibrate all other secondary units.