Re: Window Foil

[invalid@xxxxxxxxxxxx (Beachcomber)]

>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