I've been given a sample Honeywell capacitative proximity sensor by a client. He wants me to build a small micro-based project to interface with it. The sensor is shipped in a bag labeled "992AA12AN-A2", and the documentation for "992 series" sensors consists of four letter-sized sides, most of which are multilingual translations of warnings and mechanical specs. The electrical documentation supplied with this sensor is a quarter-page and not very meaningful to me. I've photographed it at
The device has a blue wire, a brown wire and a black wire. Looking at those diagrams - I presume they relate to different versions of the sensor - I assume that the blue wire is supposed to be +ve, the brown is -ve, and the black is output. But when I connect a 10VDC supply and a scope, all I see on the output is 60Hz hum. I added a 500 ohm resistor between the "output" line and ground, and still all I get is hum. The device also doesn't seem to be drawing any appreciable current.
The only info I can find on the web is a bunch of people offering to sell me the datasheet, and one company saying that they have stopped selling it and now sell someone else's sensor. Does anyone know how these devices are supposed to work?