In article om,
"Dave Liquorice" writes:
On Thu, 27 Jul 2006 23:05:41 +0100, Dave Plowman (News) wrote:

But you need a reasonable knowledge of this sort of wiring as they
aren't supplied with DIY instructions.

This is true but it isn't rocket science, you just need to pick up on the
rather strange terminology used. I suspect this is deliberate to make it
look difficult and complicated when in reality it's **** simple.

Much of it is, but some things are less obvious and come with
experience. Type of sensor to use and how to position it for
maximum effectiveness with least risk of false alarms is one
such. If you are DIY'ing an alarm without this experience, I
would stringly suggest you don't connect an external sounder
until you've had a long period of running with no false alarms.

Some time ago, I did a write-up of a number of the dual-tech
detectors I have used. This is unlikely to be directly useful
now as the products will have been superceeded, but it might
give you a feel for the type of variation between products,
and how you might select one over another:
http://groups.google.co.uk/group/uk....5f61bd5da0c158

--
Andrew Gabriel