Condensation monitors like EE46 are used to check on the condensation on chilled ceilings and to prevent condensation from forming on critical areas of HVAC systems. As it can monitor dewpoint, it can also be used for systems near dewpoint. For dewpoint, the device measures on relative humidity, thanks to the temperature coupling between the condensation monitor and the environment. This relative humidity is measured through high-quality capacitive RH sensor. When it reaches the switching point of 90% RH, the output will start giving signals for initiating control. It could be increasing the initial water temperature, reducing the cooling capacity, switching on the heating and so on. Contamination protection is provided for the electronics and sensors. The device can be mounted on pipes, ducts and walls.