Transmitters of the EE21 series have been developed for high-precision measurement of relative humidity and temperature. EE21 transitters are available for wall and duct mounting as well as with the very useful snap in - mounting kit which allows a quick and easy exchange of the transmitter. Outputs can be selected between voltage and current. An optional radiation shield which supplies a forced ventilation is recommended for use with outdoor applications. A special protection coating for the sensing element (code - HC) permits the permanent use in very polluted ambiences. A high humidity calibration should be employed for applications in humidities lasting > 90% RH (Code - CA01).