Re: Wireless Motion Detector Recommendations...

[rabsparks@xxxxxxxxxxx]

crabbs wrote:
> I'm looking at the DSC and Ademco wireless motion detectors, but they
seem
> pretty expensive  ($80-$150). Is this what I should expect to pay or
is
> there a decent alternative for a bit less that's compatible with a
DSC 864?
>
> Thanks.
>
> BTW, what does PIR stand for and why are some detectors PIR and some
not?

First of all, often times in security you get what you pay for. Buying
an inexpensive device and you might well be buying yourself a "false
alarm generator" (a sensor that's so poorly designed that you are
besieged with what most people call "false" alarms (actually a "false
alarm" is an alarm generated by the device's electronics without
outside stimulation while a "nuisance alarm" is an alarm caused by an
outside stimulus other than an intruder.)

>From your question, it sounds as if you're an end-user and not a
dealer, installer or consultant. That puts you at a significant
disadvantage in working out which sensor phenomenology is best. In
addition to PIR, you could also have: microwave, ultrasonic, active IR,
seismic/pressure, impact/glass break, video motion detection, et
cetera.

Each sensor phenomenology has its strong and weak points. Therefore one
sensor type may be used in one room while another type might best be
suited for another room. Since you apparently don't have experience
necessary to determine which sensor phenomenology (not to mention which
sensor types react to various room conditions), you're taking on a
quite a bit yourself.

If you're simply replacing a sensor installed by someone who has that
experience, then that's one thing. And you can probably simply replace
the defective sensor, making certain that you keep the exact location
as the one you're replacing and set the sensitivity at the same level.
But if you're adding to your existing system, i'd suggest that you find
a qualified alarm installer in your area and let him/her make sure that
you're not going to have trouble with the new sensor, its type (PIR,
glassbreak, etc), its location, and sources of nuisance alarms in the
room/area.

Now right about now, you're thinking, "He's an installer: what else
would he recommend?" Wrong. I am a consultant and do not provide
equipment to my clients. There's a lot more to selecting sensors to
meet specific conditions than one might think.

rick