[volt-nuts] impedance bridges

[Dick]

On May 26, 2012, at 5:00 AM, volt-nuts-request at febo.com wrote:

> Message: 1
> Date: Fri, 25 May 2012 18:12:38 +0200
> From: Fred Schneider <pa4tim at gmail.com>
> To: Discussion of precise voltage measurement <volt-nuts at febo.com>
> Subject: [volt-nuts] Impedance bridge information
> 
> >>>
> Can someone give me a hint what to search for. For instance the right name of such a bridge ( i think Z/Y or admittance cq impedance bridge) and what is important so I can determ if they are for what I want and not just a allround LCR bridge.
> 
> I want to measure the more extreme things like ESR, fF, delectric proporties/losses ect but for most I love old precision measurement instruments which make you think about what you do and have lots of knobs instead of menus.
> 
> Fred PA4TIM

Hi Fred -- I think the best all-around (meaning most accurate when cal'd) manually-operated general bridge is the ESI 250DE. 4 digits resolution worst case with built in 1kHz oscillator and detector, and with DC source and detector for resistance. Mine is overall better than 0.1% on C and L, and runs about 0.03%or better  on resistance. ESI made all their own resistors and the Dekapot at the heart of the 250DE is just terrific. The range resistors on mine all checked better than 0.01% measured with my HP 3458A.

A good alternative is the GR 1656 -- but the 1650 and 650, etc are really not in this class, lacking an accurately readable dial.

Dick Moore