The EE03 is a compact inexpensive, pre calibrated, plug-in module that is digitally communicating and fully temperature compensated from -40F to 185ºF (-40 to 80ºC). It's two wire digital protocol will travel up to 100 ft over a twisted pair. One unique feature of this module is that it can be used to measure surface humidity concentrations, which can be used to predict if dew point conditions are eminent. This product is deal for building and equipment monitoring including economizer and mold control for HVAC applications. With the digital signal delivered directly to a microprocessor, calculation of other humidity variables such as enthalpy, dew point, or humidity ratio can be easily and inexpensively calculated. (AirTest can also recommend micro based calculation algorithms you may want to utilize). 0-100% RH, ±3%, -40 to 185ºF (-40 to 85ºC).