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Gary Schafer
May 12th 04, 04:58 AM
I am looking for an accurate voltage source around 12 volts to use to
check calibration on digital voltmeters. .01% would be nice.

Does anyone know about the 3 terminal voltage reference chips
available? Would they do the job?

Thanks for any help.
Gary K4FMX

Bob
May 12th 04, 06:22 PM
Yes the three terminal references should work just fine for you. I have
tried some of them and they are great, right on the button.

Hook up two of them and measure the difference with a sensitive voltmeter.
They are very close.

Bob

Bob
May 12th 04, 06:22 PM
Yes the three terminal references should work just fine for you. I have
tried some of them and they are great, right on the button.

Hook up two of them and measure the difference with a sensitive voltmeter.
They are very close.

Bob

John Walton
May 12th 04, 11:02 PM
0.01% of 12V is 1.2mV, most 3 terminal references have noise which is much
greater than this. Something like a Linear Tech LT1963A will get you into
the tens of uV -- but all the associated components have to be tightly
wound.

If you go into the Linear TEchnology webiste (www.linear.com) and look at
the application notes there is an article by Jim Williams which describes a
20 bit DAC -- too complicated to get into here -- what you can do with one
of these DAC's would take a Fluke 3330B calibrator two decades ago.
www.linear.com/pub/document.html?pub_type=app&document=92

If you are going to calibrate DVM's you'll find some real bargains on EBay
under the business equipment/test equipment/calibrator section. It helps if
you have a university with a well equipped lab -- you can compare purchases
with standardized equipment.





"Gary Schafer" > wrote in message
...
> I am looking for an accurate voltage source around 12 volts to use to
> check calibration on digital voltmeters. .01% would be nice.
>
> Does anyone know about the 3 terminal voltage reference chips
> available? Would they do the job?
>
> Thanks for any help.
> Gary K4FMX

John Walton
May 12th 04, 11:02 PM
0.01% of 12V is 1.2mV, most 3 terminal references have noise which is much
greater than this. Something like a Linear Tech LT1963A will get you into
the tens of uV -- but all the associated components have to be tightly
wound.

If you go into the Linear TEchnology webiste (www.linear.com) and look at
the application notes there is an article by Jim Williams which describes a
20 bit DAC -- too complicated to get into here -- what you can do with one
of these DAC's would take a Fluke 3330B calibrator two decades ago.
www.linear.com/pub/document.html?pub_type=app&document=92

If you are going to calibrate DVM's you'll find some real bargains on EBay
under the business equipment/test equipment/calibrator section. It helps if
you have a university with a well equipped lab -- you can compare purchases
with standardized equipment.





"Gary Schafer" > wrote in message
...
> I am looking for an accurate voltage source around 12 volts to use to
> check calibration on digital voltmeters. .01% would be nice.
>
> Does anyone know about the 3 terminal voltage reference chips
> available? Would they do the job?
>
> Thanks for any help.
> Gary K4FMX

artie
May 13th 04, 04:31 AM
One of my favorite gadgets is the Datel DVC 8500 voltage calibrator.
Small, fairly stable, +/- 19999 mV via thumbwheel switches, plus
trimming. They pop up on eBay aperiodically (one currently listed,
going for $31, and recently calibrated -- a deal. Item 3814748987).




>
> "Gary Schafer" > wrote in message
> ...
> > I am looking for an accurate voltage source around 12 volts to use to
> > check calibration on digital voltmeters. .01% would be nice.
> >
> > Does anyone know about the 3 terminal voltage reference chips
> > available? Would they do the job?
> >
> > Thanks for any help.
> > Gary K4FMX
>
>

--

artie
May 13th 04, 04:31 AM
One of my favorite gadgets is the Datel DVC 8500 voltage calibrator.
Small, fairly stable, +/- 19999 mV via thumbwheel switches, plus
trimming. They pop up on eBay aperiodically (one currently listed,
going for $31, and recently calibrated -- a deal. Item 3814748987).




>
> "Gary Schafer" > wrote in message
> ...
> > I am looking for an accurate voltage source around 12 volts to use to
> > check calibration on digital voltmeters. .01% would be nice.
> >
> > Does anyone know about the 3 terminal voltage reference chips
> > available? Would they do the job?
> >
> > Thanks for any help.
> > Gary K4FMX
>
>

--

John Walton
May 13th 04, 02:09 PM
I bought a Fluke 3330B for under $50 -- I was stunned that it was in perfect
cal -- I just used it for an article that had a microprocessor controlled
power supply -- nice to have the Fluke so that you don't have to play around
withthe code or worry about a keyboard. It is a beast, however. I bought
a second "parts" unit in case anything goes wrong with the first one.

When you play around with these things you begin to purchase high quality
cables and connectors. I didn't know a "Seelback" from a humpback!

Jack

"artie" > wrote in message
.com...
> One of my favorite gadgets is the Datel DVC 8500 voltage calibrator.
> Small, fairly stable, +/- 19999 mV via thumbwheel switches, plus
> trimming. They pop up on eBay aperiodically (one currently listed,
> going for $31, and recently calibrated -- a deal. Item 3814748987).
>
>
>
>
> >
> > "Gary Schafer" > wrote in message
> > ...
> > > I am looking for an accurate voltage source around 12 volts to use to
> > > check calibration on digital voltmeters. .01% would be nice.
> > >
> > > Does anyone know about the 3 terminal voltage reference chips
> > > available? Would they do the job?
> > >
> > > Thanks for any help.
> > > Gary K4FMX
> >
> >
>
> --

John Walton
May 13th 04, 02:09 PM
I bought a Fluke 3330B for under $50 -- I was stunned that it was in perfect
cal -- I just used it for an article that had a microprocessor controlled
power supply -- nice to have the Fluke so that you don't have to play around
withthe code or worry about a keyboard. It is a beast, however. I bought
a second "parts" unit in case anything goes wrong with the first one.

When you play around with these things you begin to purchase high quality
cables and connectors. I didn't know a "Seelback" from a humpback!

Jack

"artie" > wrote in message
.com...
> One of my favorite gadgets is the Datel DVC 8500 voltage calibrator.
> Small, fairly stable, +/- 19999 mV via thumbwheel switches, plus
> trimming. They pop up on eBay aperiodically (one currently listed,
> going for $31, and recently calibrated -- a deal. Item 3814748987).
>
>
>
>
> >
> > "Gary Schafer" > wrote in message
> > ...
> > > I am looking for an accurate voltage source around 12 volts to use to
> > > check calibration on digital voltmeters. .01% would be nice.
> > >
> > > Does anyone know about the 3 terminal voltage reference chips
> > > available? Would they do the job?
> > >
> > > Thanks for any help.
> > > Gary K4FMX
> >
> >
>
> --

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