Kemo m152 12v rain detector sensor relay module pre assembled kemo m152 p kemo s m152 rain sensor module combines a liquid sensing plate and a 12v normally open relay contact to produce a switching operation controlled by the detection of rain or snow the relay is activated when rain is detected on the sensor plate and de activated when water is no longer present integrated heating avoids water staying on the plate once it has stopped raining potential projects include motorised windows