On 02/04/2018 15:04, Brian Reay wrote:
On 02/04/18 14:17, Dave Plowman (News) wrote:
In article ,
Â*Â*Â* Brian Reay wrote:
I was discussing fitting a burglar alarm with my son-in-law and the
problem of their cat occurred to me.

While they could confine the cat to a room not covered by a PIR, the
layout of their house would make this far from ideal in a number of
ways.


I can't believe I'm the first person to think about this problem- what
to the millions of people with cats/dogs do?


Pet proof sensors. Basically, the lens is designed to ignore low moving
objects like cats or dogs. Work OK here.


I'm not a cat owner but don't they climb on sofas etc?

Some sensors are like that, but not all. Others use a PIR which is
designed to ignore small, moving heat sources, while still picking up
larger ones.

Ours also combines this with microwave sensing - which I assume is also
size dependent - and only triggers when both PIR and microwave sensors
are triggered.

SteveW