Pet Immune motion detectors

[mikefamig]

What is the groups experience with pet immune motion detectors? I am adding a couple of Elk wireless motions and would like to hear if it's worth a couple of extra bucks. Does it really work? It seems to me that my dog would find a way to set the thing off whether it had pet immunity or not. She moves around a lot.
 
Mike.

 

[dementeddigital]

I'm curious about this, too.  I'm considering adopting a 100 pound German Shepherd, and I'm thinking that even the "pet immune" PIRs would still trip.

 

[Del91574]

They don't work off weight...it's mass. Think about the mass of a 40# dog vs. a 100# dog.....then factor in where the area the motion of the animal is likely to be (low, except for cats). Just like a quad element PIR. They need to see the appropriate mass and movement in a specific pattern to generate an alarm.
 
That's why the installation papers always say don't aim them at stairs or anything the animal can climb within X amount of feet. They work, but you need to also consider a few things, which sometimes include selective masking to avoid false alarm issues.
 
I've installed quite a bunch over the years (actually from the first gen units) and they work if you follow the directions. Dogs are the easiest to generally set the motions for. Cats climb. I've installed them where the HO had a 100+# dog or a pair around 60-80#'s. The old DS835i's I was putting in before the blue line detectors came our specified either a 100# dog or 2 60# dogs or a few cats...and they work, you just need to adjust the MW properly.

 

[mikefamig]

I ordered with pet immune.
 
It cost about ten dollars more and with the elk motion you can turn it on or off so it's a ten dollar option. I find it very interesting how this stuff works and sometimes doesn't work. I already have one in my kitchen but haven't taken the time to experiment with it. I plan to point the new one at my front door and maybe I'll add a rule to beep when there is motion to see how the two behave with the dog running around when we are home.

 

[dementeddigital]

They don't work off weight...it's mass.

 
I didn't mean to imply that they worked off weight.  Of course they couldn't.  I would assume that it would be surface area facing the sensor.
 
I had some pet-immune sensors in an old house, and I had two cats which would terrorize each other from time to time.  They never tripped the PIR sensors.  I think that a big dog probably would, though.  Of course the dog makes a pretty good motion sensor, too - with teeth.
 
DEL, how do you selectively mask a PIR?  Is there some paint for the lens or something like that?

 

[Del91574]

I didn't mean to imply that they worked off weight.  Of course they couldn't.  I would assume that it would be surface area facing the sensor.
 
I had some pet-immune sensors in an old house, and I had two cats which would terrorize each other from time to time.  They never tripped the PIR sensors.  I think that a big dog probably would, though.  Of course the dog makes a pretty good motion sensor, too - with teeth.
 
DEL, how do you selectively mask a PIR?  Is there some paint for the lens or something like that?

Electrical tape or some manufacturers have masks that come with the detectors and trial and error, spending time setting them up. A lot of guys out there don't do things like mask detectors or adjust them, more of a slap it up and get paid, then worry about the problems afterwards.
 
Dogs are never a real deterrent, no matter what people tend to think, just the fact of the matter. Maybe a slight deterrent for a casual opportunistic break-in.
 
The detectors work based of the location and size of the IR signature in their FOV.

 

[dementeddigital]

Dogs are never a real deterrent, no matter what people tend to think, just the fact of the matter. Maybe a slight deterrent for a casual opportunistic break-in.

 
My wife agrees with you.  She is from South America, and she says that when people want to break into houses there, they typically just poison any dogs.
 
Thanks for the info on selectively masking.  Is there any way to do that with MW (or dual PIR/MW) detectors, too?
 
These look nice: http://www.visonic.com/Products/Wired-Detectors/Next-duo-k9-85-pets-immune but with the additional MW sensor, can they still be masked by dealing with both sensors somehow?

 

[Del91574]

I don't install straight PIR, PI or otherwise. Just not worth it for me based on a callback or performance. I'd rather spend for a better detector up front.
 
As far as masking, it depends on the detector. Whether or not you can get to the lens, mirror, or whatever form of optic it has. Some motions don't have that option.
 
MW should always be adjusted to the bare minimum needed to obtain capture performance as it can pass through building walls and glass. Part of the "mystery" false alarms that many experience is installing a dualtec without actually adjusting the technologies to the environment.
 
I've never really liked Visonic's motions. Just based on performance of ones I've worked with or seen installed elsewhere....the K9's have been on the market at least 10+ years and haven't truly changed. The EN standards don't really mean much, just that the detector can be installed in a EU graded system (grade 2, which is allowable for monitoring) which isn't a performance spec.

 

[Dogman]

Del:  What PIR motions do you like?:  My old DSC is giving up and need a replacement.  It is in an entry way with alot of glass and faces west.  I do have a 40 pound dog which has never set of the existing DCS but it never seemed to work great when testing .  Sometimes would not trigger when testing.

 

[LarrylLix]

Mass and weight are the same thing, at sea level, on earth. The difference is not worth bothering with unless you are installing MS units in outer space or another planet.
 
These are well defined scientific terms that somebody has mixed up.

 

[mikefamig]

I can understand how a motion detector or camera can see what percentage of it's field of view is covered by a moving object but I question how a motion detector can measure either mass or weight.
 
Mike.

 

[Del91574]

Mass and weight are the same thing, at sea level, on earth. The difference is not worth bothering with unless you are installing MS units in outer space or another planet.
 
Somebody has their scientific terms mixed up.

Not true sir, if you want to split hairs.
 
The apparent mass of say, a 100# dog to a 100# human are going to be inherently different to a "dumb" detector. Does that mean that the detector is going to false alarm with a 120# dog and a 80# human in the same FOV? The detector can't weigh an object, so the device's operation is based off the apparent mass of the object being detected by the sensor via it's logic. Same reason why I can run a PI detector with 100# PI, but the rating is decreased when you have, say 2 60# dogs.....the apparent mass of the two animals is greater than the single 100# animal.
 
https://en.wikipedia.org/wiki/Mass_versus_weight   (though I don't necessarily like citing wiki as fact)

 

[Del91574]

I can understand how a motion detector or camera can see what percentage of it's field of view is covered by a moving object but I question how a motion detector can measure either mass or weight.
 
Mike.

Percentage of FOV, then it comes down to apparent mass of the object and distance from the detector. The better units have a mask on the "creep zone" immediately below the detector that generally must be left intact, blinding the detector to objects within the first X feet of the detector and below it's height. The IR signature of a larger mass is going to be higher than that of multiple smaller items that are spread out, then factor in the pulse count change in the detector's FOV. (the whole 2-3 steps you can make before alarming).
 
This is why many dualtec units specify the amount of immunity (old DS835 and 835I's were 1 100# dog, 2 60# dogs or up to 10 cats) but at the same time, there's no PI once you start getting into the upper FOV of the detectors, which is where the neat coverage pattern icons that come with the detectors come into play (included for a reason)

 

[RodneyE]

Pet immune motion detectors normally disregards motion caused by animals under 80 pounds.Most security system uses passive infrared motion detector technology to monitor the heat change in the particular area. Pet immune motion detectors are good as they reduce the risk of a false alarm. Motion detectors are beneficial in a lot of ways. I read a blog from think protection that mentions how a motion detector is better than a door or a window contact  
. Though most pet immune motion sensors would not work on dogs because they generally tend to be above 80 pounds and smaller animals like birds,cats and ferrets also would not count.