Top positive review
54 people found this helpful
on September 9, 2013
I'm a professional alarm service guy and have installed a number of these. The key is testing, there is a tool that is specifically for these detectors. Dropping keys, breaking bottles in trash cans, etc will NOT work on today's glassbreak detectors (years ago, this would work). The "flex" signal is a thud just before the pitch of shattering glass. If these are located and adjusted properly (as per the instructions), it's rather difficult to intentionally or accidentally trip these.
Out of the box, the sensitivity comes at maximum - from experience, in most residential settings, maximum is too high and tends to cause false alarms. Make sure you install them across from the protected glass (preferred), on the ceiling, or on an adjacent wall, but not on the same wall as it. If you have access to an FG-701 tester to make sure it's adjusted and located properly, that's even better.
Now, on to the real part of my review. I have a Vista-20P system with three of these installed on my first floor in addition to hardwired motions and window contacts. I have each installed per the instructions, and their sensitivity has been tested with the proper FG-701 tool. I've been doing a lot of work to my 100-year old windows, including taking the sashes out to strip the paint, reapply fresh glazing putty, and repainting the sashes. Just an hour or so ago, I was trying to free up a top sash that had been painted shut, and I accidentally broke the glass. I heard the door chime, and saw my kitchen glassbreak (about 15 feet directly across from the window) had tripped. Shortly thereafter, I armed the system and recorded a video. I went outside, and using a hammer, broke more of the glass as if I was trying to enter. The detector tripped the first time (much to my surprise!), the panel went into alarm and my siren sounded.
Even as a pro I've always been a little leery about glassbreak detectors being reliable 100 percent of the time because there is no way to functionally tell if it's working, but this helps even me sleep a little better at night. Still, I would rely on glassbreak detectors as a backup detection method to window contacts, which should be your first line of protection.