[volt-nuts] Agilent calibration

[John Phillips]

no, this is work and it is not that accurate. that is just our best guess
(about 1 ppm) of an old fluke 732B. We compare with our other 732Bs. Any
available 3458As are monitoring the Flukes. Each hour a program picks up
the Mean Max Min standard deviation from each meter average them together
and plot the Mean for all the meters... Some times I have had 10 meters but
sales have been up so I am down to 1 this week.
 I have about 5000 hours of data.
Most 3458As come in within a few ppm of this standard.
We send 3458As out to Agilent for repair and calibration then check our lab
standards.
Old standards and meters seem to be a lot more stable than new ones.




On Wed, Aug 14, 2013 at 9:45 PM, Demian Martin <demianm_1 at yahoo.com> wrote:

> Do you really have a .01 PPM voltage reference? A personal JJ? That's
> taking
> this hobby to a new level.
>
> >
> > Daniel,
> > They are made like that... Problem is with drift.
> > When you cal a 3458A the first step is to short the inputs and wait for
> the
> > thermals to die. Then you do a Cal 0 and the incitement stores all the 0
> > offsets for that set of terminals. they you switch to the other set and
> do
> it
> > again.
> > Next step is apply 10 votes to the terminals or in my case it is
> 9.9999411
> and
> > enter cal 9.9999411 front and back set of terminals. remove the voltage
> and
> > plug in a 10k standard resistor and in my case enter cal 9999.884 for
> front and
> > back. In most cases AC does not have to be done. The meter is comparing
> its
> > measure values with the values entered and calculates the correction
> factor
> > to be used each time a value is displayed.
> > Most good meters now days do have a null function so you can look at
> drift
> > or compare 2 values.
>
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-- 
John Phillips