Re: Driveway Alert Sensors

[Steve Uhrig <Steve@xxxxxxxxxx>]

On 8 Oct 2005 16:07:56 -0700, "Mark Thomas" <mrt@xxxxxxxxxxxxxx>
wrote:

> How about false alarms due to falling leaves? Deer? Small animals?
> Heavy rain/snow? I'm not sure about an infrared beam solution.

Deer trip it. I have it looking about 4 feet high across the driveway,
so nothing smaller does. Not that many deer cross my driveway, and
none during the season.

Takes a lot of intelligence to discriminate a deer from a man. Same
size, same weight. The IR is looking for a heat difference from
ambient moving from one zone to another (of I believe 16 zones).

Leaves and snow do not affect it.

Every spring for about 3 days, the sun is at an angle where it glares
off something and causes a few nuisance alarms a day from shining into
the thing.

But all I'm doing is turning on lights and starting some Pelco Spectra
cameras in a scan sequence, so no harm is done from a false. It rarely
falses. If someone is driving or walking in, they also hit other X10
hardwired motion sensors so I know if they're heading towards the
house, the shop or the barn.

Steve

*********************************************************************
Steve Uhrig, SWS Security, Maryland (USA)
Mfrs of electronic surveillance equip
mailto:Steve@xxxxxxxxxx  website http://www.swssec.com
tel +1+410-879-4035, fax +1+410-836-1190
"In God we trust, all others we monitor"
*********************************************************************