[volt-nuts] 3457A - should I preserve SRAM contents, or purposely corrupt them by removing power?

[Dr. David Kirkby (Kirkby Microwave Ltd)]

On 25 January 2016 at 15:40, Poul-Henning Kamp <phk at phk.freebsd.dk> wrote:

> --------
> In message <
> CANX10hALwjXT+8eV8LYWdqy9EEZ+AnaWihgqEyRzntsY80v9RQ at mail.gmail.com>
> , "Dr. David Kirkby (Kirkby Microwave Ltd)" writes:
>
> >I'm wondering if I would be better purposely removing the battery, and
> >putting a short across the SRAM so I ensure the contents are definitely
> >lost. My logic is that
>
> I would save the content before doing that, so that I could compare it
> to whatever I got back from calibration.
>
> My experience so far says that there probably is a GPIB command which
> can read out the memory, but of course you still need to know the
> address-space layout.
>

I've not looked myself, but I did see a note on the web there was no
documented command to do read out the cal data on a 3457A. But in any case,
unless I know how to interpret those values, a bunch of meaningless 0's and
1's is not going to be a lot of use. Of course, if I could save them I
would, then in the event someone ever figures out what the numbers mean, I
could do a comparison.

It would be nice to know if the meter is in/out of spec, but to me, I think
having it put as close as possible to correct is more worthwhile, even
though a metrologist who gets their meter calibrated regularly would no
doubt see it different.


Dave