[volt-nuts] Fluke 343 arrived, what would you do?

Fabio Eboli FabioEb at quipo.it
Fri May 11 07:28:01 UTC 2012

I reread the message I i forgot the "what would
you" do question in the text :)
This is my first calibration device, so I'll make
lot of questions :)

Here is it:
to explain things, I will use the 343a to
calibrate DCV of my sol. 7061 that lost cal constants.
The solartron permits to enter the values at
cardinal points using the keyboard.
The 343a precedent owner used a freshly calibrated
8846 to read the values from the 343a before
sending it to me.
Given the fact that the keithley readings and
the reported values from the owner are not
far apart I'm thinking to allineate the
solartron to the keithley and not use the
reported values.
The keythley 2015 is built around an lm299
and was calibrated back in 2004, surely
it has drifted in these years, but surely
I wansnt there when the 343 owner took the
measure with his instrument, so I cannot
trust on more than the other.
At least allineating the 7061 and keithley
will make easy spot check big differences
between the two.
Whad do you think?

A pair of considerations:

1- The solartron 7061 once calibrated maintains
very good agreement between the ranges,
for example setting 18.88...V on the 10Vrange
and I see the same number (with less digits)
on higher 100V and 1000V ranges,
is this sign of good linearity?
The 19999... full range counts of the solartron is very
handy, compared with the crippled 11999.. of the

2- The 343 has slight differences between
the "1" range of one selector and
the "X" range of the precedent (lower digit)
selector, is this due to drift of the
beta string resistors?

Now I can transfer the DC calibration form one
instrument to another at resonable accuracy,
next I have to find a cheap way to transfer
resistances and AC voltages.

Thank you for your patience :)

Fabio Eboli <fabioeb at quipo.it> ha scritto:

> Hello, today I got a fluke 343a, I talked about
> it on this list last month.
> It's a little dirty, and has some problems
> in the 1000V range:
> when I put it on the 1oooV and the selectors
> are at 10 0 0 0 0 0 0 0 the unit starts well,
> but when I select lower voltages the units
> goes in current limitation at 500V descending,
> and at 480 raising from lower values.
> At values <480V and >200 the unit goes well,
> and the problem is worse at voltages <=200V,
> where the protection trips and disconnects
> the output.
> Does anybody have experience with these calibrators?
> Any clue will be appreciated.
> Fortunately the ranges I need for the 7061 work well,
> the 343 precedent owner measured the values with
> it's meter an reported the readings.
> I've measured these values with a keithley that
> I bought recently, the instruments are powered
> from 5-6 hours and the temperature is a little
> less than 20°C.
> The difference seem of less than 20ppm at 100 and 1000V, and
> less than 10ppm at 10V and less, the keythley was
> calibrated back in 2004.
> Here a photo:
> http://www.flickr.com/photos/14336723@N08/7170879284/lightbox/
> Fabio.
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