Guest Chewie Posted January 29, 2005 Share Posted January 29, 2005 Thats a bit to cryptic for mr eng Can you elaborate I have also edited my previous post Link to comment Share on other sites More sharing options...
Guest Posted January 29, 2005 Share Posted January 29, 2005 Thats a bit to cryptic for mr eng Can you elaborate I have also edited my previous post 38588[/snapback] if you have a pir facing the door,you have to watch out for the postie posting the letters at 100 mph into the hallway which can cause false alarms.... Link to comment Share on other sites More sharing options...
ian.cant Posted January 29, 2005 Share Posted January 29, 2005 Thats a bit to cryptic for mr eng Can you elaborate I have also edited my previous post 38588[/snapback] It is possible that when Postman Pat chucks his wad through the box it can trigger the PIR so dont point it at the door. Point it back into the hallway. Link to comment Share on other sites More sharing options...
Guest Chewie Posted January 29, 2005 Share Posted January 29, 2005 OK thanks, but dont they look for a heat signature as well as movement. Link to comment Share on other sites More sharing options...
Guest Posted January 29, 2005 Share Posted January 29, 2005 OK thanks, but dont they look for a heat signature as well as movement. 38594[/snapback] that depends if its recorded mail.. Link to comment Share on other sites More sharing options...
Guest Chewie Posted January 29, 2005 Share Posted January 29, 2005 Link to comment Share on other sites More sharing options...
ian.cant Posted January 29, 2005 Share Posted January 29, 2005 OK thanks, but dont they look for a heat signature as well as movement. 38594[/snapback] Nice one Gaz! How a PIR works isnt the way your thinking. It see's IR energy and uses that as a reference, then if anything changes rapidly using its processors it decides if its big enough a change of reference and acts accordingly. So Imagine your nice warm floor and suddenly theres a big wet cold envelope on it. Depending on the quality of your PIR and the sensetivety set up will depend on wether you get false alarms or not. Plus a bit of luck and the weather and ............ Link to comment Share on other sites More sharing options...
Guest Chewie Posted January 29, 2005 Share Posted January 29, 2005 OK thanks so it can trigger from a rapid reduction in temperature as well as an increase, learn something every day. Link to comment Share on other sites More sharing options...
ian.cant Posted January 29, 2005 Share Posted January 29, 2005 OK thanks so it can trigger from a rapid reduction in temperature as well as an increase, learn something every day. 38606[/snapback] Which is why when on a cloudy but sunny day, when the sun pops from behind a clound and creates a hot spot on a floor it can trigger a PIR. Also if a spider walks across the sensor it will trigger because it see's a major change in its reference picture. Link to comment Share on other sites More sharing options...
Guest Chewie Posted January 29, 2005 Share Posted January 29, 2005 Thanks for all your help Ian (and everyone else) I really appreciate it. I am looking at PIR's from TLC. Wonder if you could make some reccomendations. 360 deg ceiling PIR for the garage. Either of these any good. We do have a Chincilla in the garage in a cage, could this possibly cause false alarms with these PIR's. http://www.tlc-direct.co.uk/Main_Index/Ala...cial/index.html Then I need one for the hallway, one for the kitchen and one each for the Living room, Dining room and study. Not really sure what I should be looking for out of these ones. Kitchen ? http://www.tlc-direct.co.uk/Main_Index/Ala...arsh/index.html Should I be looking at standard or dual tech for the rest ? http://www.tlc-direct.co.uk/Main_Index/Ala...larm/index.html http://www.tlc-direct.co.uk/Main_Index/Ala...Tech/index.html Link to comment Share on other sites More sharing options...
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