"Colin" wrote in message
...

"Pete Cross" 1@2 wrote in message ...
I bought 12v linked detectors and wired them into our house alarm on the
24hr loop.

Interesting idea. I was actually thinking of the actual sensor housing
having a PIR as well as a smoke detector.

There might then be a problem with the positioning of such a combined
device. Smoke detectors need to be away from the corners of walls and
ceilings to aid a fast detection of smoke and PIRs are usually placed in
such places.

--
Adam