I warn you now this will be quite a long description of my idea.

I was thinking that at presen most people's PKE's ony have working lights and maybe LED's in the creen that don register anything.

My idea is that if your doing a kid's party or somthing then you create a meter that would regiser a chemical you spray out of a can like an aerosol. The internal workings would be built and programmed to register high levels of the chemical and cause the PKE to go ballistic, though you'd probably have to find a way to spay it without it being obvious( hidden in ghost sniffer perhaps). Though it would be difficult to build a interior devise that could detect chemicals. Just a thought anyway.

Smoke detectors and Carbon Monoxide detectors work son the bases your talking about. I just don't want to be at the same party when you PKE meter starts to go ballistic cause it's a carbon monoxide detector…

How about sonar? When you get close to someone, it would go off!

What I meant is that you spray something none posionous and the built in sensor detects it. Kinda like what you're getting at Ectoman.

Sonar would be cool, but how do you do something like that?

on hyperdyne labs he has a rather small motion detector kit… rather inexpensive too i think its only 60 bucks

another solution would to put an EMF meter that has an LED display, and them move close to anythign with a motor, or circuit breakers, tvs, light swtiches…