The Pet MW motion detector is a motion sensor with one PIR and one microwave sensor. An alarm is not reported to the alarm center until both sensors detect movement. The Pet MW motion detector is an animal-immune motion sensor. It can tell the difference between persons and small animals such as pets. Whereas persons moving in the room are reliably detected, the sensor ignores pets up to 30kg. Despite the words "pet immune to 30 kg" it is possible that animals with a lower weight trigger the detector. The risk of false triggering is particularly high when the animal moves, jumps, or flies in the vicinity of the detector. The combination of passive infrared (PIR) and microwave (MW) ensures high protection against false alarms. The reason: An alarm is not triggered until both sensors – which use technically different detection methods – register movement. Whereas the PIR sensor reacts to moving heat, the microwave sensor actively monitors the surroundings for movement (similar to radar). The transmission frequency is 9.35 GHz. The best place to install the sensor is in a corner, between 2.4 and 2.7 meters above the floor. The intruder's possible direction of movement should be at right-angles to the sensor. The viewing angle of the Pet MW motion detector is 90 degrees, and the detection range – depending on installation height – up to 12 x 12 meters. You can vary its sensitivity by means of a jumper. This way you can define the number of pulses that have to be detected before the sensor opens the alarm relay.