Window Foil

It depends on which detectors you're using. Some detectors (IntelliSense, for example) are designed to detect the high frequency cracking of the glass plus the low frequency pulse caused by striking the glass. The low frequency sound depends on the glass being part of the perimeter of the space, like the skin on a drum. These are tested by thumping the glass, which in turn triggers the tester to emit a sound similar to glass shattering.

A questions for the pros about glass break detectors from an old foil installer (who did a lot of drug and liquor stores... back in the

70's).

Do you have any personal knowledge of a case where there was an otherwise properly armed alarm system with glass break detectors where the GBD failed to go off when the intruder broke in? It would seem to me that that would be the worst case scenario. I know that some of the best of them would go off during a thunderstorm, but that could happen to the foil window systems too.

A basic loop alarm seems so simple, but plunger contacts can stick, foil can partially break, motion detectors can trip from pets and air turbulance, magnetic reed contacts can fuse together.

Will the so called "Swingers" always be with us, or are there new developments in technology to minimize false alarms.

Beachcomber

properly armed alarm system >with glass break detectors where the GBD failed to go off when the intruder broke in?

Yes. That can happen when a very small section of the glass is actually broken, along a single line for example, instead of being shattered..

Yes. The detectors were made by IEI. A unit mounted on the ceiling, directly in front of a glass door completely failed in service with no warning. Fortunately, there was a PIR which detected the thief the moment he entered. Upon inspection it was found that a cap on the glassbreak's circuit board had failed, leaking an oily substance. There was no sign of lightning or other external cause for the failure.

The only worse case would be if there was no backup. Others here have mentioned that they don't like to rely on glassbreak detectors as the sole protection and this is one reason they're right. I prefer to use glassbreaks as an adjunct to door and window contacts but always recommend at least basic motion detection as a backup.

True, but properly applied foil was one of the least problematic types of detection we used. Most of our jobs were residential so I mainly used foil on basement windows. We did a fair number of commercial jobs though and foil on glass entry doors was a nuisance.

Except for when he vacations on his rowboat, Jimbo will likely continue swinging both ways.

A customer I have that I took over 3 years ago had a newer DSC system installed. I added a DSC acuity 100 GBD ontop of the door contact, DV300 motion and Window Foil they already had. The GBD was on its own zone. During the night, some kids took a brick and smashed out the front display window. The glass break didnt go off. However, the window did sound the alarm. The bell started to ring in the front of the store and scared them away. Now the strage thing is, I tested the GBD with DSC's handheld tester and it work when installed. When I went back to check it, It failed.

To this date, I will use DSC panels, Motions, but no Glass Break Detectors. I now use Rokonet.(however, I dont use their motions) So I was kinda glad that I kept the window foil connected. In the past I always disconnected the crap if I took an account over and installed GBD's. But now, if it works, I keep it connected. Then, if a window has been smashed and they replace it, I will foil the window to match the rest of the windows.

M

On the older model DSC glass breaks they used to attach the microphone to the cct board via really thin red and black wires (on the order of

32AWG). If you weren't careful mounting the unit, you'd break one of the wires. If you didn't test the unit (using their tester), you'd never know the unit didn't work. We recently took over a system in a restaurant that employed these older units. 3 out of the 6 installed had broken wires.