Re: [volt-nuts] Bohnenberger electrometer

In the lexicon of physical devices is an item called an electret. Commercially these are used in capacitive microphones. The common ones consist of polymer sheet that has been annealed in a voltage gradient. An accidental example is the swarf from methyl methacrylate (Perspex, Plexiglass) which

Re: [volt-nuts] Bohnenberger electrometer

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

Re: [volt-nuts] Bohnenberger electrometer

Yes Hendrik, same principle as the butterfly disk style, but mine use cylinders - the field exposure is radial instead of axial.  Ed ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to

Re: [volt-nuts] Bohnenberger electrometer

Something like this ? https://de.wikipedia.org/wiki/Elektrofeldmeter (German wikipedia as the english entry is less than stellar. They are called field mill.) Best regards Hendrik On 16.03.2018 19:53, ed breya wrote: There is another kind of static electric field meter that was commonly

Re: [volt-nuts] Bohnenberger electrometer

I once made the alu-foil type but also one with a jfet. The gate as "antenna" I have many meters but no static field elctrometer. (and no coulomb meter, never seen one in real life too) I like exotic meters. I  repaired (and modded) a 3 axis fluxgate meter a while back. The owner uses it to

Re: [volt-nuts] Bohnenberger electrometer

On 6 March 2018 at 09:40, Dr. David Kirkby wrote: > Sorry this is not precision voltage measurement, but it is not unrelated. > > As a radio club project, we are building a simple electroscope, with no > active components. The gold leave variety would work, but