fitting a pir near roadside

[multimick]

got a job fitting a pir near side of road (4 metres away) to contol 2 led floods any tips to avoid cars or pushbikes setting it off ,i can point it down and buy one with sensitivity control but any other tips please

 

[DPG]

That photo looks staged.

 

[Ray Pooley]

It would've triggered if they'd jumped through the window after smashing it, though.....

Exactly. That's my point. It takes a heat signature to activate it. They are not motion sensors. They are heat sensors. You could place a lamp in front of a PIR and drag it about. It will not trigger. Leave it where it is and just switch it on and the heat from the bulb will trigger it. Try it.

 

[Ray Pooley]

That photo looks staged.

The photo was "staged". I put the brick there and took a picture of it for insurance purposes. Staff had moved it and started to clean up by the time I got there. But here's the glass and here's the window.

 

[DPG]

Thanks. I'm happy now

 

[Ray Pooley]

Thanks. I'm happy now

You're welcome.

 

[Richard Burns]

As far as I understand it, a PIR sensor has a spread of sections that are sensitive to heat, generally approximately human body temperature, though any wide range of heat source will work and the received light is focused onto the section.
Each section is looking for a change in heat reception, i.e. a presence or absence of heat, if this change occurs from one section to another, or repeatedly on one section, depending on the algorithm used by the manufacturer, then the PIR will trigger an output.
A moving incandescent lamp should trigger a PIR as it will be sending out a wide range of IR wavelengths, similarly if the lamp is switched on the detecting section will register a change in temperature as the lamp heats up from cold and as it passes the temperature range and so will also trigger.

 

[Rpa07]

My neighbours PIR detects my leafless tree, swaying in the wind

Poor Midwest and his ‘euphamism’ used to describe his ‘manhood’ ;-))

 

[Midwest]

Poor Midwest and his ‘euphamism’ used to describe his ‘manhood’ ;-))

Got me there.

 

[MFS Electrical]

My neighbours PIR detects my leafless tree, swaying in the wind

And my neighbours detects the wind and nothing else

 

[telectrix]

My neighbours PIR detects my leafless tree, swaying in the wind

what's the point of keeping a leafless tree? that's like having an alcohol free beer.

 

[Midwest]

what's the point of keeping a leafless tree? that's like having an alcohol free beer.

You silly sausage, the leaves grow back in the Spring. Watch a bit more Gardeners World, you'll get there.

 

[telectrix]

You silly sausage, the leaves grow back in the Spring. Watch a bit more Gardeners World, you'll get there.

but the beer in my glass won't grow back. i have to go to the offy. maybe i should plant a beer tree in a barrel.