Calibration of 8.5 digit multimeters in the UK
Some time ago I was considering buying a Solatron 8.5 digit multimeter. I
contacted the company that bought them, and perhaps who bought them.
Eventually I was told they could not calibrate the multimeter, but Calmet
Laboratory Services in Surry can.
A couple of weeks ago I contacted Calmet to ask about calibration of 8.5
digit meters. I was told that the calibration cost depends on the exact
meter, but was around £315 + VAT. I asked it that included adjustments if
needed. I was told no, there would be extra charges then the instrument
would require calibration again, so would be more than double the initial
price.
They said to contact them to ask about a particular meter, to get a price
for calibration and to ask if a meter can be adjusted.
I have not looked at the uncertainties of Calmet.
Given Keysight charge $777 in the USA for a basic calibration, that is
going to be at least £650 in the UK. So I conclude if a 3458A needed
adjusting, Keysight would be cheaper, but to check if within
specifications, Calmet would be cheaper.
Personally I would not consider using them for calibration of a 3458A, but
for other meters it might be an option.
Although I would rather use Keysight for a 3485 if I had a 3458A, would it
be possible to adjust a 3458A oneself for free, just by using the
measurements from Calmet (assuming they give measurements)? If one knew
the 10 V DC voltage was reading 12 ppm low, and 10 k resistance 20 ppm
high, could one calculate the register values to increase voltage readings
by 12 ppm and decrease resistance values by 20 ppm? Or is their some
complexities I am overlooking?
Dave
Dr. David Kirkby,
In message CANX10hCJVA1WvvTJg7UsQcgk0RS0Eoni4Xs93oYO45uco+vqNQ@mail.gmail.com
, "Dr. David Kirkby" writes:
So I conclude if a 3458A needed adjusting, [...]
There is nothing in the 3458A that can be adjusted.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
On Wed, 7 Aug 2019 at 21:35, Poul-Henning Kamp phk@phk.freebsd.dk wrote:
In message <
CANX10hCJVA1WvvTJg7UsQcgk0RS0Eoni4Xs93oYO45uco+vqNQ@mail.gmail.com>
, "Dr. David Kirkby" writes:
So I conclude if a 3458A needed adjusting, [...]
There is nothing in the 3458A that can be adjusted.
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Not even by software? I thought there were calibration constants.
I guess I should look at a 3458A manual, but given I don’t own a 3458A, I
don’t have a great incentive.
Dave
--
Dr. David Kirkby,
In message CANX10hCVy9UPspXW1dGggb+tUEafn0mQwvnU=aVjfegcZDVX5g@mail.gmail.com
, "Dr. David Kirkby" writes:
So I conclude if a 3458A needed adjusting, [...]
There is nothing in the 3458A that can be adjusted.
Not even by software? I thought there were calibration constants.
You short the inputs, front&rear, run "CAL 0" on both of them.
You connect approx 10V to front or rear, run "CAL $voltage"
You connect approx 10kOhm to front or rear, run "CAL $resistance"
Done.
There is an AC-flatness calibration, following the same basic
schedule, but unless you plan to measure or sample non-audio-range
frequencies, you can ignore that.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
Hi, is there any known way to detect if equipment might have been subjected to a temporal displacement?
Thinking measuring known predictable deterioration in components, say if the flow of time was significantly
different in an area this could be compared with a background level.
In this case also measuring known isotopes present at manufacture would also work as the decay rate eg of
63Ni is known to be a constant so any deviation should be detectable with a high accuracy counter.
From: volt-nuts volt-nuts-bounces@lists.febo.com on behalf of Poul-Henning Kamp phk@phk.freebsd.dk
Sent: 08 August 2019 08:16
To: Discussion of precise voltage measurement; Dr. David Kirkby
Subject: Re: [volt-nuts] Calibration of 8.5 digit multimeters in the UK
In message CANX10hCVy9UPspXW1dGggb+tUEafn0mQwvnU=aVjfegcZDVX5g@mail.gmail.com
, "Dr. David Kirkby" writes:
and follow the instructions there.