A method in use 40+ odd years ago for measuring atmospheric electric fields was to use a slotted rotating disk rather than the rotating cylinder.
A matching stationary or counter rotating disk IIRC was used either in front or behind the rotating slotted disk the the sensing disk was behind both. Bruce. > > On 17 March 2018 at 07:53 ed breya <e...@telight.com> wrote: > > There is another kind of static electric field meter that was commonly > used over the past few decades for monitoring charges/voltages in work > areas dealing with sensitive semiconductors. It has a small motor > spinning a hollow brass cylinder that has a radial hole or slot that > alternately shields and exposes a center cylinder inside, which is the > pickup electrode. This action causes a small AC signal on the electrode, > that can be amplified up to represent the electric field strength from > any nearby object. The signal is then rectified and trips a comparator > and LED indicator if the level exceeds a certain amount. > > I have a couple of these units, but have never experimented with them > yet. They don't show any kind of readout or provide a measuring signal - > just the LED warning of excessive (unknown trip point) static charge > nearby. I figured someday I would modify one up and add a signal output > port and a sync output from the motor, allowing a lock-in analyzer to > read the result over a wide range, and maybe even be fairly accurate or > calibrate-able. > > Ed > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.