Re: Electrometer design? (fwd)

[Steven Roys <sroys@xxxxxxxx>]

---------- Forwarded message ----------
Date: Sat, 10 Jul 2004 23:47:43 -0700
From: Richard Hull <rhull@xxxxxxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Electrometer design? (fwd)

I have several vibrating reed instruments made by Cary and Keithley.

The reeds in these are gold plated plates which are vibrated in a vacuum
(vibrating capacitor actually)  with the charge deposited on the reed.  The
virbration rate can be 60-400 hz on most reeds.  On the keithly, this all
contained in a special vacuum tube no longer available.  All vibrating reeds
are contained in a sapphire insulated gold plated head unit separate from
the main readout instrument.

I have never tried to do a work around to create a vibrating reed
electrometer, but anyone is welcome to try this, perhaps, uphill battle.

Richard Hull

----- Original Message -----
From: "High Voltage list" <hvlist@xxxxxxxxxx>
To: <hvlist@xxxxxxxxxx>
Sent: Saturday, July 10, 2004 7:10 PM
Subject: Re: Electrometer design? (fwd)


> Original poster: Steven Roys <sroys@xxxxxxxx>
>
>
>
> ---------- Forwarded message ----------
> Date: Fri, 09 Jul 2004 15:18:57 -0700
> From: Ed Phillips <evp@xxxxxxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: Re: Electrometer design? (fwd)
>
> Charles:
>
> I haven't looked at those links yet (will do, of course), but before I
> do I have a couple of questions someone here may be able to answer.
>
> 1.  How about vibrating reed electrometers?  Anybody know anything about
> them.  Seems to me a very easy and cheap vibrating "reed" could be made
> with a small loudspeaker.
>
> 2. Has anyone looked into using varicaps or the like?
>
> Ed
>
>