Does it cost a lot to have infared beams as part of a home security system?

Answer by  knightmare (1231)

Not particularly, they are just a transmitter and a sensor and gets triggered when the sensor can't "see" the beam. These actually come in a lot of garage door kits now, and is the same general technology that will stop closing a garage door if something is in the way. It shouldn't be too costly.

Answer by  jkc (258)

Passive infrared detectors can be fitted as a retrofit to your existing installation at a relatively low cost, these can be set high to ignore pets.