I wish to install a basic alarm system to protect kitchen back door, dining room patio doors (both at rear) and front door/hallway downstairs and just landing upstairs which should be enough for attack via any bedroom. Only thing is we have two cats 15 and 17 years old,not overly active but still walk about and have access to all the house. What sort of alarm system should I go for, PIRs seem simple to source and install but are there any that ignore cats and only react to humans?
No, but you could probably site them so that they wouldn't 'see' a cat on the ground. Even a bit of black insulation tape is enough, when placed across the lens to restrict the field of view of a PIR.
Sorry, this is rubbish. Pet Immune sensors are readily available, from RS for one, and they work perfectly well. I fitted several in a house with an extremely large active cat and never had it trigger them.
Typical specs:
"1 or 2 animals up to 13.4 Kg" "Pet immunity up to 33 Kg a dog or 4 cats"
No, impossible. What "pet proof" PIR's actually do is see the area on just one plane - horizontal from the sensor. Normal PIR's see on at least three planes - usually 7 degrees 22 degrees and 35 degrees from horizontal. Some have more sensitivity and include full 90 degree protection both vertically and horizontally.
Relying on the fact that your pet will not venture higher than the height of the unit itself it needs to be positioned at least the cat + tail (!) above any surface that the cat could get on - and that obviously includes kitchen worktops.
Now then... problem is that worktops are around three feet high so that added to the cat + tail is around 5 ft. So, positioned on the wall at 5ft high your "pet proof" PIR will probably not detect your car BUT it won't detect anyone less than 5ft in height either and considering that many burglars are kids you immediately have a problem.
Also consider that burglars do what they do for a living and tend to be anything but stupid. A quick look through your window will reveal the fact that your PIR is half way down you wall and is therefore pet proof. The thief then simply enters the room and stays low.
In my experience pet proof detectors (sometimes called pet alley too) are a waste of time. They offer minimal protection and should the pet venture any higher than usual (up against a window for example) then you have a false alarm.
Consider using alternative type of protection such as perimeter protection u sing contacts, inertias or vibration detectors. If you don't fancy that or if it's not feasible then consider a dual tec PIR/microwave which has sensitivity settings and pet alley on the PIR section.
The ones I've got had a choice of lenses and also allowed some adjustment in the horizontal plane. So they're mounted in the 'conventional' place. They seemed to cope ok with a cat when I last had one, but she was fairly old and didn't jump that high. ;-)
Yes. I'm familiar with those types of PIR. Problem is that if they're mounted in the conventional place and a pet alley lens or PCB position is selected the overall sensitivity is quite poor in relation to a standard setting/lens. You can't have it all ways. Pet proof always means less coverage/sensitivity. The other common method is to use multiple pulse count. Most PIR's have the capability to pulse count to 4 but to be honest the average person moving at normal speed will only cause the average PIR to actually trip once or maybe twice at a push so it would be possible to walk through the room without activating the alarm.
So, it's either per alley dual-tec, perimeter protection or poor protection!
The other line of thought of course is does the kitchen actually need space protection anyway. Kitchens are notoriously bad for alarms. Cookers, hobs, hoods fridges and washing machines can all cause false alarms with space protection whereas perimeter is OK with these. Smaller kitchens, like bathrooms, suffer from condensation problems and that isn't good for any sensor. OK, if there's a Hi-fi, TV, PC and a whole load of NEFF appliances then the area may need protection but if it's just a bog standard kitchen why bother?! Protect the "house", not "the kitchen"!
agreed and all very good providing your cat doesn't jump onto a worktop within range of the PIR! These new technology PIR's are brilliant but are far from fool proof. Expect false alarms and if you don't get any it'll be a bonus! In any event use a dual tec unit in a kitchen as I mentioned earlier and as illustrated on the above pyronix site.
A dual-tech microwave/infra-red detector that goes by weight immunity is the best for animals that are prone to jump about on furniture and things. Pyronix, along with many other makers, have a range of these designs. The Pyronix are marked with a product number which ends with PI.
With respect Dave... PRESSURE PADS??!! Christ, they went out with the arc! They are unreliable, cause more false alarms than any other device, damage carpets and are extremely inconvenient when it comes to moving furniture etc. around. They are also (most of the time) noticeable as there is usually an obvious bump in the carpet. They also wear out as we stand on them in normal day to day living. As for "switches" on doors and windows... a complete and utter waste of time and money. Contacts on windows are all well and good providing the burglar opens the window! Most of the time they smash through leaving the opening frame in place and therefore not causing an alarm. Contacts on doors is also (in my opinion) a waste of time - except when necessary to start a setting or an entry procedure. Doors and windows should always be locked and bolted thus rendering any contact useless in anything other than a complete gross attack. I specified alarm systems for over 25 years and always avoided contacting doors and windows (front door was usually contacted to form the exit/entry route) and as soon as space protection was introduced in the late 70's pressure pads were dropped like a very hot brick in favour of them. Ultrasonic first, then PIR's and microwaves etc.
Pressure pads?! I suggest contacting your local museum as they may be interested in buying them from you!
Sorry Dave, I had total respect for your postings until you admitted that one!
I don't think these are the same ones. There was nothing in the instructions for the ones I installed about positioning them with regard to animals. The method of operation you describe does not rely on the weight or size of the animal which is quoted in the spec.
In my installation one is aimed at a flight of stairs, no way the cat could be on the stairs and not in range of the detector, yet it does
*not* set it off, but a human anywhere in range does.
the simple kind of pet resistant movement sensor uses a special lens to lift the infra red beam above the level of the animal. fine with dogs that stay on one level but not cats that can climb. but the good news is there are now movement detectors (been around about five years) that allow for one or two cats (or other animals) up to a certain weight. They need careful siting, usually not permiting the animals to be closer than 6 feet ie no good positioning them above a table or chair. They do work and ive fitted a number with no trouble. they are less sensitive than a normal sensor but do the job.
I've not had one false alarm, they've never failed, and they're nowhere near furniture.
If they're simply thrown under a carpet, yes. If they're cut into the underlay they're undetectable - unless you're really checking for them
Mine are in the most heavy trafficked part of the house - and are fine.
I've been burgled once and had a couple of attempts (before the alarm was fitted). Each time they levered open - or attempted to - a sash window. Most casual burglars don't want to crawl through broken glass - would you? Same with my neighbours that have been burgled.
Of course they're locked and bolted. But on a wooden sash, such locks won't resist a determined attack with a jemmy, etc.
Strange how I never have false alarms - unlike the professionally fitted systems either side of me. ;-)
Oh so the bump becomes a dip instead of a bump! Oh please!
Have you looked at them? Checked their condition? Is the foil and foam protruding from the split edges yet?!
Yes, if I did it for a living like burglars do!
The PROPER locks will.
False alarms are caused by two main factors - pressure pads and poor installation techniques such as not soldering joints etc. I happen to know this as I've been an alarm engineer for many many years, unlike yourself.
That's because the detector has a micro processor to analyse the IR field and so the detector is "deciding" not to activate when it sees the cat.
What I am saying is that these type of sensors do work but are not fool proof. If, for instance, your cat gets a fright and charges up the stairs the detector will "probably" go into alarm. People with a dog anything bigger than small should also avoid these sensors as the IR field from the dog could cause an activation as the PIR has to alarm should there be any possibility of an intruder and a medium to large dog will produce the same amount of IR energy than a small human (kid).
Few more pointers: always use a dual detection triggered control panel. Numerous alarm systems without this feature have been fitted, they frequently lead to repeating false alarms, and the owners give up using them.
Second be careful where you mount door opening detectors, as door warping or wind can set them off. They are a big source of false alarms.
Third cover your desired area with more than one technology. Only when both detect an intruder do you want the system to go off. Most sensors are prone to some cause of false alarm or other.
Glass break sensors are useful (not foil strips).
There are burglar identifying paints and burglar trapping smoke bombs, and of course CCTV if you have money to spend. Note only a high res colour one is worth having - you cant seriously identify someone off a junk grade picture.
If you fit all this, make sure youve got locks worth having to start with. Night latches are mostly hopeless, and 2 lever locks are easy to open, use 5 levers and more than one locking point.
Finally tamperproof wiring is a bonus to protect against the more determined attackers, but you dont need this in most cases.
Of course it all costs money, hence the temptation to go for a cheapass solution. Trouble is, 3 PIRs and a single event tripping system isnt really a solution.
Another approach towards security is to use laminated glass in the openings big enough for burgers to get in through. They'll have to bash in numerous imes to get through, each time making a breaking glass noise. They soon give up, as every glass smashing noise is a real risk to being caught. Repeated smashing is a dead give away. But retrofitting this isnt really a cheapie option.
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