Re: Wireless Motion Detector Recommendations...

["CatMan" <liberaltrash@xxxxxxxxxxx>]

Very good response rabsparks. I have a question: As a consultant, have you
ever come across the requirement to filter or de-sensitize a PIR? Reason I
ask is I am using a combination of Visonic PIR's and X10 MS13A's. I know, I
know - the X10 stuff is you get what you pay for. However, by
experimentation with mounting/aiming them, they have become fairly accurate.
The X-10 and Visonic PIR's do false on bright sunny days even though I have
them mounted under eves. I am fairly sure some of the problem is UV light
that may be setting them off. I have used tape to block part of the lens'
coverage but that didn't really work. I have read somewhere that people have
used some type of filter material that either passes only IR light or
filters out UV light. DO you think this would be possible?

I found a few photography web sites that discuss creating an IR passing
filter using un-exposed developed IR film. I have not tried this yet but
plan to do. I also found a web site that sells UV filter material made from
clear colorless polyester film. DO you think this may work? Maybe using just
common window tinting material may work.

Ideas?

Comments?

Thanks!





<rabsparks@xxxxxxxxxxx> wrote in message
news:1113668292.196876.193510@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> 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
>