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Thread: Outdoor PIRs with microwave and dual PIR - false alarm immunity?

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    Default Outdoor PIRs with microwave and dual PIR - false alarm immunity?

    Hi guys,

    I have read on here that outdoor PIRs are prone to false alarms due to the environment (trees/plants moving in the wind, rain, temperature change etc)

    For a rear garden that is fenced, when beam install wasn't practical, if these were immune to false alarms they would be perfect for burglary prevention.

    Has anyone got experience with ones that have microwave and dual/quad PIR? Are these prove to false alarms? They state that 30kg or greater body mass is required to alarm therefore a bird flying past shouldn't provide a false alarm..
    I have read about some in the US that sweep therefore only alarm when detected as moving at least a set distance - wonder if these are immune from the environment false alarms?



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    Anti sway, dual industrial pyro quad, dual channel MW blah blah blah and they still activate.

    Think about it. You've got a device that designed to detect motion in an environment with lots of motion. Yes, outdoor detectors have improved in recent years but they still can't ignore environmental extremes well enough to detect only intruders reliably.

    Outdoor detectors usually do one of two things. False alarm with startling regularity or fall asleep because its too hot.

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    Not sure I agree with Drift.

    Outdoor detectors today are being unfairly judged due to:
    a) Inferior technology from a few years ago
    b) Poor installation practices.

    Detector placement is important indoor and outdoor. You should know I *hate* false alarms. Have seen lots of outdoor sensors (usually PIR) covered in cobwebs and other muck. The fact is detectors require a certain level of care and feeding. That in turn requires a certain type of customer. Would you put them in everywhere? No. For everyone? No. But they do have some terrific application.

    I'm really starting to enjoy some of the wireless external PIRs. Partly because they're easy to deploy, but also because they can be relocated if required. Have been experimenting with some of the Paradox external PIRs, wired and wireless. No false alarms to date (around 3-6 months in the field). Now admittedly this is a very non-scientific experiment and I can't say what they've missed either, but haven't had any break and enter at those sites which they missed, touch wood...

    If you ever travel to Israel, they are in use *everywhere*, even on cheap residential flats. They're cheaper there because they're made locally e.g. Risco and there's no Australia Tax. However there is a lot of market for this stuff and it is getting better and cheaper. I would say Drift should reconsider, just as I'm coming to terms with wireless, which I hated a couple of years ago.

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    Not sure I agree with Drift.

    Outdoor detectors today are being unfairly judged due to:
    a) Inferior technology from a few years ago
    b) Poor installation practices.

    Detector placement is important indoor and outdoor. You should know I *hate* false alarms. Have seen lots of outdoor sensors (usually PIR) covered in cobwebs and other muck. The fact is detectors require a certain level of care and feeding. That in turn requires a certain type of customer. Would you put them in everywhere? No. For everyone? No. But they do have some terrific application.

    I'm really starting to enjoy some of the wireless external PIRs. Partly because they're easy to deploy, but also because they can be relocated if required. Have been experimenting with some of the Paradox external PIRs, wired and wireless. No false alarms to date (around 3-6 months in the field). Now admittedly this is a very non-scientific experiment and I can't say what they've missed either, but haven't had any break and enter at those sites which they missed, touch wood...

    If you ever travel to Israel, they are in use *everywhere*, even on cheap residential flats. They're cheaper there because they're made locally e.g. Risco and there's no Australia Tax. However there is a lot of market for this stuff and it is getting better and cheaper. I would say Drift should reconsider, just as I'm coming to terms with wireless, which I hated a couple of years ago.

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    Whilst I hear what you're saying I still disagree. I will concede the technology has come a long way to what it was 15 years ago when the first PIRs were first seen (VX40-(hey look it talks!)) however the Risco Watchout to which you refer has changed little since it's release some 7 years ago. Whilst the devices can compensate for environmental conditions with on board processing, and installers can adjust a plethora of sensitivity settings on board, you can't change what these will ultimately devices detect. Microwave will still detect physical motion and PIR will still detect temperature changes. The device can't tell the difference between a large dog, kangaroo, a bird or cat up close, and a person. Neither can any installer fully control the environment in which they install the device once they've left site. No matter how much planning you put into choosing the right location, one latent pigeon and it's all over.

    All of the outdoor devices currently available have their downfalls and require significantly more maintenance from both the installer and client to ensure trouble free operation than do internal devices. Electric fences and PE beams require constant weeding, mowing and removal of debris in the area, just as outdoor PIRs require one to ensure cobwebs are kept off.

    I've tried and tested many outdoor devices in a range of conditions and continue to do so in the hope that the manufacturers have finally cracked it. I'm yet to be satisfied enough with the results that I'll install them without the client first signing a disclaimer. Perhaps I'm a little too pedantic, but then again, this is the security of people and property we're talking about. Some take it more seriously than others.

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    Thanks guys for the comments so far.

    On this install, I should give more details, it is a paved part of the back garden, the house is a U shape so will be pointing to a wall and also mostly undercover (a pagola over the top). There are a few small plants but on the edge of its range. No dogs and no Kangaroos.
    It certainly would not cover the whole back yard but working on the principal that any burglar once they climbed over the high fences, they would walk around and check all the doors are locked.

    But I have a CCTV camera in this location and on motion detection I have caught a bird flying past twice in the last 6 month.. Are the best outdoor detectors intelligent enough to not false on a bird...

    I do have a little bit of faith in the external sensors. I have a cheap Swan drive way alarm for the front of the house (saves having a door bell) and haven't had a false since having it (sure I will do it time though). The top of the range microwave/dual PIRs should be 10 x better than this
    Last edited by matt_in_perth; 19-10-12 at 02:52 PM.

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    Quote Originally Posted by matt_in_perth View Post

    I do have a little bit of faith in the external sensors. I have a cheap Swan drive way alarm for the front of the house (saves having a door bell) and haven't had a false since having it (sure I will do it time though). The top of the range microwave/dual PIRs should be 10 x better than this
    The best still can't ignore something that's right in front of them. Stick your finger in front of your camera and take a photo. It'll occupy the majority of the shot. A bird in front of the best external PIR is no different. A bird will have the the two key characteristics required to active the device. It's warm and it's moving.

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    Quote Originally Posted by Drift View Post
    The best still can't ignore something that's right in front of them. Stick your finger in front of your camera and take a photo. It'll occupy the majority of the shot. A bird in front of the best external PIR is no different. A bird will have the the two key characteristics required to active the device. It's warm and it's moving.
    Almost like you need multiple sensors and triple validation! I suppose you could have it as a silent zone but then there is no point as they would be in without knowing it.
    Only other option is an outdoor PIR separate from alarm system with a recorded message. Police have been called!

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    Quote Originally Posted by matt_in_perth View Post
    Only other option is an outdoor PIR separate from alarm system with a recorded message. Police have been called!
    The criminals will need to start carrying a recorded message which says "Hahaha pig's arse!".

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    Quote Originally Posted by downunderdan View Post
    The criminals will need to start carrying a recorded message which says "Hahaha pig's arse!".
    LOL

    The problem these days is some criminals don't care about making noise or being seen. Recently in Perth there has been multiple cases of criminals forcing there way into homes in broad daylight approx 3-4pm, sometimes with people home, not like in the old days where they would only break in around the back where no one could see them.
    Front windows smashed or kicking down door in view of many other houses or people, 3-4 with a weapon of some kind (baseball bats), faces covered, take what they want and out within 2 minutes into the high performance sports car they stole the night before...

    Not much you can do about that unless you make your house like a fortress....
    Last edited by matt_in_perth; 22-10-12 at 01:37 PM.

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    Matt,

    When governments make it hard for people to keep firearms at home, they send a message to criminals that they are unlikely to be challenged in someone's home.

    There really is nothing quite like the sound of a shotgun being racked to say "get out of my house"...

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    A few Farmers I know loved there pump action if they heard people on the farm just open the back door and click clack, if they didnt move then let one go in the air

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