Cooling ceilings, critical areas in HVAC and technical installations, which are operating close to the dewpoint temperature, need an early alarm system against the forming of moisture, because of the potential danger of condensation. The condensation monitor EE46 is designed for such applications and can be installed in a few seconds on pipelines, walls, and ceilings. A special coating protects the sensor and electronics against dirt and dust, for a longstanding, stable and above all maintenance free operation. The fast, high accurate humidity sensor is exposed to the temperature of the surface of the object by means of a thermal conducting foil. If the preset set point of 90 %RH is exceeded the device switches a potential free contact and provides a signal enabling to take early counter measures, e.g. to increase the temperature of the water in the pipe, to decrease the cooling power or to turn on the heat. In addition, a LED on the enclosure indicates the actual status. The condensation monitor is designed to be powered by 24 V ac/dc and is a solution for the early detection of condensation.