[Test-Equipment] rms voltmeter?

[Richard Knoppow]

----- Original Message ----- 
From: <k0ewu9 at juno.com>
To: <test-equipment at mailman.qth.net>
Cc: <test-equipment at mailman.qth.net>
Sent: Saturday, January 19, 2008 4:17 PM
Subject: Re: [Test-Equipment] rms voltmeter?


> HI ALL, i found an old westinghouse lab type ac voltmeter, 
> actually a
> dynamometer type movement
>
> which is dc as well as ac...The original factory cal chart 
> was still in
> the lid, the unit was sold as a lab type with an accuracy 
> of 0.25%
>
> or better.  I took it down to our local ISO cal lab and 
> checked it againt
> the new fluke  cal standard,
>
> it is still within the accuracy stated in the chart, it is 
> running about
> 0.15 to 0.18% at half or full scale, pretty good for
>
> a 65 year old thing?
>
> jack      K0EWU9 at juno.com
>
    Old passive instruments like meters, resistance 
standards, and bridges actually get better with age because 
they stabilize. That is any drift will become progressively 
smaller so that periodic calibrations vary less and less 
with time. Its also probably in a beautiful wood box.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk at ix.netcom.com