Expert: Dave Neuweiler - 2/22/2001

Question
is it true that some home motion sensors will not pick up on pets and set off alarms

Answer
Hello, Benny, and thanks for your question. There are two answers: "yes," and "no." Let me explain.

Motion detectors and pets have never mixed well, but with the explosion of home security systems over the last decade, equipment manufacturers have tried to make their motion detectors more resistant to false alarms caused by pets.

There are two basic schemes. The first is to install the motion detector in such a way so it won't be able to detect a pet's motion. This is usually accomplished by creating a "pet alley." Normal detector installation provides a pattern of coverage that extends from near the cieling to the floor. A pet alley is arranged so that the coverage is approximately waist-high or above. Two drawbacks: a knowlegable burglar could crawl under the coverage and evade detection; cats climb furniture and might still be able to cause a false alarm.

The second scheme involves a detector which can estimate the size of the "target" that it senses. For "man-sized" targets, an alarm is initiated; for small targets like cats and dogs, the target is ignored. Drawback: the detectors cost more; I can't give you pricing information, though.

A 3rd alternative is to protect just the openings (doors and windows) that a burglar would use to gain entry to your home. This may be more expensive than "pet-resistant" detectors; ask your salesperson to price the system each way. (If he or she won't, then a call to another protective services company may be in order.)

Hope this helps; if you need more information, please submit another question!

Sincerely, Dave