[volt-nuts] AC Voltage Measurement Standards

[ben]

Hello,   For my 5cents worth, I also found Fluke 8506A's to be satisfactory 
- so long as they work. I only have one good remaining unit that does AC 
volts as well as DC.  I like the HP 3458A for AC volts, but always need to 
apply corrections for serious AC volts work.    A better solution I now use 
is the Datron 4920 units which are an order of magnitude more accurate than 
the 3458A across their full bandwidth. However, be aware of their input 
impedance and selection of cables - always use short coaxial. The 4920 
impedance is around 100k to 400kohm (mostly frequency dependant) and this 
also varies during its sampling period. Otherwise they are great units, in 
the same ball park as a Fluke 5790 but way cheaper.  For an AC source I 
thoroughly recommend the Datron 4200 or 4700 series, which are also way 
cheaper than the near equivalent Fluke 5700. 
Ben




----------------------------------------
From: acbern at gmx.de
Sent: Wednesday, July 09, 2014 9:29 PM
To: "Discussion of precise voltage measurement" <volt-nuts at febo.com>
Subject: Re: [volt-nuts] AC Voltage Measurement Standards 

J.L.,
it really depends on what level of accuracy you are looking for. The gold 
standard obviously is the Fluke 792A. That is probably not an option. The 
Fluke 8606 is more on the lower end side (dont get me wrong, compared to 
the 792A), it does not really bring much improvements compared to the 3458A 
operated in the AC SYNC mode, but maybe it is good enogh for what you want 
to do. In that range are also e.g. the R&S ac voltmeters, but their focus 
is more in the higher frequency area.
Very good accuracies are achieved by thermal converters (Ballantine...). 
You can do DC to AC comparison measurements with a few ppm accuracy. But 
measurements are slow, and you need a nanovolt meter.

I personally did the following: I got a Ballantine 1605A transfer 
voltmeter. This is comparable to the 792A in a way, except it was much 
cheaper. It is automatic, much easier to use than the Fluke 540 and goes up 
to I think 100MHz. This can be used for percision calibrations as a working 
standard. The calibration of this meter as well as others (e.g. the 3458A 
in its AC mode) I am doing with a set of thermal converters (0.5V to 100V). 
One of which (10V) has been externally calibrated up to 30MHz, cal of the 
others are derived from it. That way I am deriving everything from a very 
precisely (few ppm) calibrated 10V TVC. Overall, this saves cost on the 
calibration side, allows for high accuracy and measurement speed is good.

> Gesendet: Mittwoch, 09. Juli 2014 um 06:20 Uhr
> Von: "John Phillips" 
> An: mitch at vincentelectronics.com, "Discussion of precise voltage 
measurement" 
> Betreff: Re: [volt-nuts] AC Voltage Measurement Standards
>
> J. L. ,
> I do not know what level you are willing to pay for. I do not work in a
> real high end lab but we seem to get by with checking our secondary
> standards with a 3458A before and after we send it to gary to be
> calibrated. We use our 10 volts and 10K resistor to calibrate the 3458A
> before we send it in and then after. We look at the before and after 
data
> as well to come up with new values for the units. Comes down to using 
the
> 3458A as the primary standard filtered by our history. The different AC
> measurement methods in statistical mode can give you a good idea where 
your
> AC values really are.
> 
> I would like to know how that compares with what the extra hardware can 
do.
> 
> 
> 
> On Tue, Jul 8, 2014 at 7:52 PM, Mitch Van Ochten  
mitch at vincentelectronics.com> wrote:
> 
> > Joe,
> >
> > I used a Fluke 540 for a while, and also the Fluke 8506A.  The Fluke 
540 is
> > MUCH more difficult to use. You need to flip the switch between two
> > positions rapidly and the results you get depend somewhat on how 
"rapidly"
> > you make the transition. For AC volts the 8506A seems very nice.
> >
> >
> > Best regards,
> >
> > mitch
> >
> > -----Original Message-----
> > From: volt-nuts-bounces at febo.com [mailto:volt-nuts-bounces at febo.com] 
On
> > Behalf Of J. L. Trantham
> > Sent: Tuesday, July 08, 2014 9:46 PM
> > To: Discussion of precise voltage measurement
> > Subject: [volt-nuts] AC Voltage Measurement Standards
> >
> > I've been thinking about adding an AC Voltage Measurement Standard to 
my
> > shop.
> >
> >
> >
> > It would appear that most of these have to do with thermal converters.
> >  Does
> > anyone have any thoughts about this?
> >
> >
> >
> > I've been thinking about a Fluke 540B, 8506A, or a collection of A55
> > Thermal
> > Converters.  I have accurate DC measurement tools and DC standards.
> >
> >
> >
> > I would appreciate any thoughts.
> >
> >
> >
> > Thanks in advance.
> >
> >
> >
> > Joe
> >
> > _______________________________________________
> > volt-nuts mailing list -- volt-nuts at febo.com To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > and follow the instructions there.
> >
> > _______________________________________________
> > volt-nuts mailing list -- volt-nuts at febo.com
> > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > and follow the instructions there.
> >
> 
> 
> 
> -- 
> John Phillips
> _______________________________________________
> volt-nuts mailing list -- volt-nuts at febo.com
> To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> and follow the instructions there.
> 
_______________________________________________
volt-nuts mailing list -- volt-nuts at febo.com
To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.