Glass Break Detectors

The Alarm Association of Florida has developed some of the best training programs for use in the alarm industry. We have concentrated in the areas of codes, standards, procedures and regulations that govern the way our profession should work. We do generic training on installation best practices and share ideas and methods for training the end user on the operation of their equipment. We expect technicians in our courses
to already have skills in electronics, electrical circuitry and mechanical aptitude.

What we don't do in training is individual device/component specifications, the proper application and use of a device and the conditions for when or where a device will work.

This comes down to each company's policies and the procedures they use to instruct their sales, service and installation teams in product knowledge and application.

One of the challenges I have faced over the years is in the residential arena. Many if not most homeowners get alarm systems after a break-in. The police come out to write a report for their insurance company and the victims ask them questions about security.

Most of the time when I'm sitting with homeowners after a break-in they tell me that the police (who are the authority in their minds) have told them they need a security system with glass break detection devices. This way the alarm is sounding before the burglars even get inside.

This sounds wonderful to a traumatized homeowner. The problem I have experienced is that in most cases a long range glass break detector is ineffective due to the type of environment homes have.

If you install a long range glass break detector to protect a store's front windows where the glass will never be covered, there are tile or wooden floors, no solid obstructions between the window and detector, no window tint or impact glass and the detector is mounted, adjusted and tested correctly to the manufacturers specifications by a trained knowledgeable installer using the right testing equipment … then it should work fine.

I've spoken with installers and service techs that tell me they don't have a glass break simulator or don't feel they need one. Instead they pound on the wall and rattle their keys or stand under the detector, clap their hands and hiss through their teeth to test it.
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Some just install it and don't try testing it at all. They send signals by pulling wires on the control panel. This is where a person's character and moral compass comes into play.

I have been in many homes where a long range glass break detector was mounted on the ceiling in the bedroom hallway centrally located in the house. The homeowner was told by the sales rep that this device has a 25 to 30 foot range in all directions so all the glass will be protected in their 1500 square foot home. Then the installers show up and know if they don't install this job they won't get paid so ... they install it!!!

The way glass break detector manufacturers reps have trained in the past is that these devices work on line of sight within the prescribed distance range. It triggers an event when it hears a low frequency thud or FLEX, followed by a high frequency shatter. If you're standing outside the building looking in through a window and you can see the detector then that window should be protected. You can't have any solid obstructions between the device and the glass. It can't hear through walls, around corners, through doors or behind itself and the glass panes must be a minimum of one square foot in size.

That means the glass must be at least 12 inches tall and 12 inches wide NOT 6 inches by 24 inches. (if I am out of date on this info please let me know)

Some rooms are considered DEAD because they have sound absorbing objects that kill the frequencies. In dead rooms you need to extremely shorten the recommended distance for them to work. You should avoid HOT rooms like tiled bathrooms. If the toilet seat drops, the rubber hitting the porcelain creates a low frequency thud that bounces around off the tiles and creates a high frequency follower that triggers the detector and a siren.

Your customer will love that in the middle of the night.

So lets look at what a long range glass break detector has to contend with in a residential
environment. We have:
(1) thick sound absorbing furniture that gets moved or added by the homeowner
(2) plush sound absorbing carpets and area rugs
(3) textured wall paper (that might be added after installation)
(4) window treatments and valances
(5) vertical and horizontal blinds
(6) pull down shades
(7) inside shutters
(8) curtains
(9) fabric wall hangings
(10) window tint (no shatter)
(11) impact glass (no shatter)
(12) room dividing screens that the homeowner moves around
(13) slamming cabinet doors (many kitchens are hot rooms)
(14) barking dogs that jump on furniture, walls, doors and windows
(15) loud booming thunder
(16) sliding glass doors that break into 10,000 pieces with no shatter frequency
(17) burglars that cut glass
(18) burglars that remove glass
(19) Jalousie windows (too narrow to detect)
(20) Awning windows (many are too narrow to detect)
(21) people drop plates on tile floors (hot room effect)
(22) television shows can trip them
(23) stereo music can trip them
(24) incorrectly placed or improperly adjusted devices
(25) untested devices
(26) burglars using automotive glass break tools (no low frequency thud or flex)
(27) burglars using Ninja Rocks (no low frequency thud or flex)

All of these conditions or situations in a residence can cause either false alarms or undetected/missed burglaries. The long range glass break detector does have its place in our industry. It is a perimeter detection device and should be used in conjunction with interior protection. Professionals are careful and mindful of why, where, when and how to use any alarm equipment.

A good home security system includes back-up inside trap zones. These can be motion detectors in vulnerable areas or inside door, cabinet or drawer contacts that are normally closed and programmed as interior follower zones. Statistically, when burglars get inside a home they first go everywhere and open things throughout the home in the first 20 to 30 seconds. They look for anyone in the home and for all the ways to escape in case someone arrives. After that, they start looking for the good stuff. Better to detect burglars 5 to 10 seconds after entry than to miss them completely.

The only thing that can stop a smash and grab is a homeowner with a shotgun. What a security system stops are burglars being in the home long enough to get to all the good stuff while destroying the house and the homeowners mental sanctuary in the process.

Remember: Our customers rely on us to be Security Professionals.

Hope you enjoyed this. Please know your comments are welcomed and as always,

Thanks for Your Support