To analyze Trace moisture is of great significance in the production and use of technical gases as well as in the production of pipes of small diameter. Trace moisture levels must not exceed the specified values in medical applications and many other production processes. This applies also to processes in the micro-electronics industry and in certain areas of the chemical industry. The Phosphorus pentoxide method has proved itself particularly suitable to analyze trace moisture. It is an absolute measurement in the course of which available water is decomposed. The devices produced by dr. wernecke Feuchtmesstechnik GmbH are equipped with a patented sensor check which monitors accuracy during operation. Due to the compact design and fast response, dewpoint transmitters with aluminium oxide sensors are also suitable for application in this area.