IR detector problem - affected by high winds.

[Terry Casey]

My thanks to everbody for their suggestions but might I clarify a few details?

The PIR is on the front of the house and windows are not involved.

The CH flu is at the rear of the house and emerges through the roof, so is several feet above the PIR which is below gutter level. Also, during recent problem periods, it has been on the leeward end of the house.

The PIR (and lamp) are angled downwards so as to prevent nuisance to neighbours and false triggering from passing pedestrians (I can walk along the footway close to the low front wall without triggering it).

Heating of the wall is not possible - when the sun comes round to the front of the house it only shines on the outside of the wall.

There are no trees or bushes within range of the detector, only some small shrubs which are reasonably wind resistant.

Spiders? Wouldn't they cause problems irrespective of whether it is windy or not? The PIR is fairly new and, as far as I know, is well sealed (but I will inspect it closely in daylight.)

[Jeff Layman]

Indeed - an easy way to check if the IR led is working using a digital camera (or smartphone these days!).

I was in fact replying to Tricky Dicky's comment that the remote control for his PIR sensor didn't seem to work through the window. That seemed strange to me.

I've often wondered if plants behave differently in their ability to reflect IR light, and that might also add to the variability in experience people seem to get in what appear to often be similar situations. Without considering what effect purple, red or yellow-leaves might have, it seems that even green leaves can vary in their reflectance:

That is interesting. Could you hide a PIR detector inside a black sack to disguise it?.

[Dave W]

I have been in a care home for two weeks recuperating after an operation. There was an en-suite bathroom behind a door in my bedroom, and there was no switch on the light in there. Instead it was turned on for 5 minutes by PIR movement sensors on both sides of the door.

The door faced my bed, and when I moved, the light came on, shined through the gaps round the door and woke me up. So i didn't lie on that side.

I got fed up with this and tried to negate the sensor facing me by covering it with aly foil, and that stopped the red LED indicator coming on, but still the light came on when I waved my arms about.

Then I managed to unscrew the faceplate with a tiny key I had, and cut the wires to the pcb with my nail scissors. Amazingly the light still came on when I moved my arms about.

Then I covered the sensor on the other side of the door with foil - still the light came on. I didn't sabotage that sensor because the light needed to be turned on when someone was in there.

It seems that somehow I was waving warmth through the gaps in the door and triggering that sensor, even round the foil.

A nurse told me other people had complained, and all the sensors were on hair trigger. She suggested I should make a complaint via their residents review app on her tablet, which I did.

I would have disabled the inner sensor temporarily by unscrewing the terminal block output wire, but I had nothing that would turn the deep-set screw.

[charles]

last weekend, I was in a village hall, not mine, and wentb to the loo, The light came on as I went into the room, I went into thecubilce and closed the door, after a few seconds the light went out. It didn't come on again until I opened the door. Luckily there was sufficient daylight coming in through a window.

[Terry Casey]

I left it for a day to let the monsoon pass over but looked yesterday.

Absolutely no way for even a momey spider to get in there!

I will have to assume that it is just some of the bushes moving in the wind. It isn't easy to get to the controls so I won't bother adjusting the sensitivity as on non high wind nights it works exactly as we want it to.

[Terry Casey]

So after using all that foil you wre still foiled in the end!

Didn't you think to plug the gap round the door with toilet paper? I'm sure you could have scrounged some sticky tape (or plaster!) to hold it in place when the door was opened!

[Dave W]

I plugged the gap on the top with a towel, but it didn't help, perhaps because of all the other three gaps. Dave W

[Dave W]

If you meant plug the gap to stop the light, I didn't have anything suitable. I had already looked through all the drawers in the 'Crafts Room' - not even sticky tape - the foil was kindly brought in by a visitor and I held it in place with blue-tack borrowed from the cleaners tick-sheet. The door opens both ways so nothing round the edge to stop the light. I felt like a prisoner of war.