On Tue, 29 May 2012 19:26:41 +0100, John Rumm wrote:

each PIR pointing across the target zone with a gap between? if so
how
would that catch persons moving in both L-R and R-L directions??
(i.e.
if PIR 2's function relied on PIR 1 being triggered first, then
wouldn;t that only work "one way"?)

Yes, with two like that - it would be one way. You could use more PIRs,
or perhaps have the two on different axis.

Or the first one covers the whole area and the second has the narrow
band.

--
Cheers
Dave.