Leaf Wetness Sensor

Source: WeatherSTEM

Leaf wetness is a measure of surface moisture on foliage (leaves of plants). Leaf wetness sensors are made of electrical plates that measure moisture as a electrical resistance change between the elements on the sensor. The sensor acts as a “fake leaf” and gives a reading from 0 (completely dry) to 15 (saturated). It also calculates the duration of wetness and can give a reading of “leaf wet hours”.