Security Sales & Integration April 2021 - 22

SMARTS & PARTS

Tech Talk by Bob Dolph

Do You Do
Windows?

COURTESY IDS RESEARCH & DEVELOPMENT

TOOL OF THE MONTH
Techs not following best practices can result in troubles,
expenses and even death. It
is important to have good
knowledge and examples. This
is why I have picked one of my
all-time favorite resources -
The Alarm Science Manual by
Jeffrey Zwirn.

Bob Dolph has served
in various technical
management and advisory
positions in the security
industry for 30+ years. To
share tips and installation
questions, email Bob at
bdolph.ssi@gmail.com. Access
content from his 15+ years as
Tech Talk columnist by going
online at securitysales.com/
author/bdolph.

▶ DO YOU DO WINDOWS? No, I don't mean
cleaning them, though your customer might
appreciate the gesture. As you may have already
guessed, I am talking about protecting windows
and similar openings. What are some of the industry's best security practices? This is our discussion for this month's Tech Talk.
Acoustical glass-break detectors (AGBD) over
the years have matured greatly. So much so that
you see them everywhere in every professional and DIY alarm system today. Did you know
that the Amazon's Alexa even now has an AGBD
app? Good, bad, you decide.
This popularity of today's AGBDs should give
one confidence in their successful performance,
right?
As Johnny Carson would say, " Not so fast, O
Great One. " Why should we not be surprised
that there is more to this technology than just
sticking a device up on the wall? Let's look at
the some of the alarm science that goes into best
practices for a professionally installed AGBD.
What causes an alarm activation from an
AGBD? Silly question, it is the sound of breaking
glass. Yes, but what kind of sound it that? Let's
take a closer look.
There are basically two types of AGBD technology. First, there's the devices that listen for
the expected unique sound signature of breaking glass. The other type of AGBD listens for a
combination of a low frequency sound, often referred to as infrasonic, from the glass flexing and
breaking, and a higher frequency signature of the
breaking glass.
Let's take a close look at some do's and don'ts
for professional AGBD application, installation
and maintenance.
DO: Read the F******* Manual (RTFM). Reliable AGBD manufacturers have taken considerable time and effort to help with your installation. In the famous words of UL 681 Standard
for Installation and Classification of Burglar and
Holdup Alarm Systems, Section 8.4.5, " A shock
sensor or glass break detector employed to protect a window shall be appropriate for the type

Security Sales & Integration APRIL 2021

SS2104 pp22-23 Tech Talk-Fireside.indd 22

bdolph.ssi@gmail.com

of window involved and shall be installed in accordance with the product's installation instructions. " Don't be proven later in a court of law
that you ignored the manufacturer's directions.
Keep sensor documentation for your records.
DON'T: Assume all glass is the same. You have
different glass flavors such as plate, laminated,
tempered and reinforced. Make sure the AGBD
and associated tester (you do have one, right?)
have settings for different types of glass. According to most building codes, glass around doorways
and big sliding doors are a few applications where
tempered and laminated glass may be used. Some
other types such as large commercial display windows might be laminated. Test accordingly.
DON'T: Consider an AGBD test finished
with placing and activating tester near a window. If you test AGBD on new construction, go
back to test when the room is fully furnished,
including drapes. The furnishings can absorb a
large amount of sound intensity. You may find
final AGBD placement behind window drapes.
Always plan on the side of caution. Place AGBD
as close to windows but avoid false alarms. Additionally, something you will only hear about here
is the danger of no alarm from high sound level
saturation. Many AGBDs when placed close to
a very large glass section, such as a commercial
display window, may be overwhelmed and just
cancel the actual glass activation. Check with the
manufacturer of sound saturation specifications,
you may be surprised.
DO: Use only testers and simulators recommended by AGBD manufacturer. Clapping
hands or throwing your keys against the wall will
test that the AGBD is working, but will it properly detect a broken window? There is more to it
and as a pro you know that. I just recently read a
DIYer's comment, " I installed the device and just
pray it will work. "
DO: Provide an annual maintenance program
for professionally testing AGBDs. This is another
good opportunity for additional RMR as room
environments change and can affect the AGBD
performance.
DON'T: Forget to take some time to educate
and train customers on their sensor technologies.
This will help to reduce false alarms.
Some other window-related alarm technologies to consider include shock sensors that can
be applied to the glass or window frames, PIR
barriers and alarm window screens.
securitysales.com

3/22/21 10:20 AM

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Security Sales & Integration April 2021

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