On Thu, 12 May 2005 21:08:35 -0700, Blue wrote:

"Edwin Pawlowski" wrote in message
news

"Blue" wrote in message
...
I have a need to monitor human activity in a building and plan to install
something in a pipe to detect water flow to do it. Don't want to reinvent
such a thing if it already exists though. Anything out there already that
I can use for this?

There are many types of flow meters. Alarms systems for sprinklers have
used them for years. But what if the water is used for inhuman
activities?

You are right that there is such as sprinkling lines but I would put such a
device in the "human" use only line.
Thinking about a captive magnet in a PVC device in the line. I would detect
movement with a wire loop and process it from there. Would want to detect
any faucet or toilet turn-on however brief. Do you know of a flow meter
that could be used or modified in this way?

Wouldn't a normal flow switch be much simpler? I do not know if they just
strap on over a hole in the pipe or mount on a tee. But they have a thin
blade of metal that flexes out of the way and trips the switch when there
is flow.