What are 6.5 Digit Multimeters Good For?

6.5 digit multimeters sell around $1000.00. For electronics development, are these $1000 multimeters really necessary? What are they good for?
Reply to
D from BC
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Measuring to PPM accuracy, and measuring microvolt-level voltages. And as a traceable standard for calibrating products.

The Fluke 8845A is excellent.

John

Reply to
John Larkin

Sometimes you need to measure a knats ass.

Reply to
mook johnson

What's the big deal? Can't they just switch to 24-bit ADC's on the cheap and get the accuracy? Or is there some special techniques required to get that resolution in practice?

Reply to
Jon Slaughter

A 2.5 digit meter can measure a knats ass. A 6.5 digit multimeter would be for measuring the presense of a knats ass while weighing a whale.

Reply to
AZ Nomad

Measurement precision and accuracy aren't the same. You mix "resolution," "accuracy," and "24-bit" in the same breath.

Jon

Reply to
Jon Kirwan

Ah.. the tool that sets the tools.

Of course there's always something better.. :P

8.5 Digit multimeter
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Reply to
D from BC

It's probably trouble to push the noise floor down with the front end electronics in the multimeter.

32 ADC
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$77 at Digikey I think that's 10 digit. 2^32 = 4294967296 Say full scale is 1V then 1st step is 232picovolts. uhuh.. I get 1mV fuzz just by shorting out my scope probe!
Reply to
D from BC

Your a freaken genius!

Reply to
Jon Slaughter

I read that this is not difficult by paralleling ADC's or using averaging. Since the noise generally is symmetric(generally gaussian) by averaging it will cancel out.

I guess it is more important that the ADC be stable but as long as any fluxuations are symmetric(such as clock jitter) then averaging should take care of most of the problems.

Yes, but maybe that is due to the scope not using that 32-bit ADC? ;)

Reply to
Jon Slaughter

Who is "they"?

An ADC needs a voltage reference and, generally, front-end differential amplifiers, filters, and attenuators. And to be a DVM, it needs a user interface, a display, and a data interface. Oh, power supplies too.

If it does AC and ohms, it needs more stuff.

John

Reply to
John Larkin

D from BC wrote in news:MPG.26034c831878edc69896e6@209.197.12.12:

and they generally have better AC volt accuracies.

the HP/Agilent 14401A is better. :-)

it's not how many digits in the display,it's how ACCURATE the meter is that matters.

--
Jim Yanik
jyanik
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Reply to
Jim Yanik

*chuckle*

Some years ago, a guy in one of the audio forums suggested that audio really ought to be recorded and delivered using 32-bit PCM, "just to make sure."

I pointed out that if one were to set the playback amplitude so that a least-significant-bit signal produced audio at the listening position equal in power to the random thermal noise of air molecules hitting the eardrum, a full-scale 32-bit signal would vaporize the power lines, explode the building and kill the listener :-)

--
Dave Platt                                    AE6EO
Friends of Jade Warrior home page:  http://www.radagast.org/jade-warrior
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Reply to
Dave Platt

True.. My scope has 8 bit voltage resolution. The point I was trying to get across was if an 8 bit system shows it's noise floor then it's probably gets increasingly difficult to control noise as sytem resolution increases(16,24,32).

Reply to
D from BC

That's seems like the averaging feature on oscilloscopes... Given time, the signal cleans up nice.

Reply to
D from BC

But have no clue as to why.

Reply to
Archimedes' Lever

Try Keithley

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Reply to
Archimedes' Lever

Which is why Keithley is better.

Agilent is good, don't get me wrong.

Don't be a LarkinTard. Instead of a lard ass, he is a Tardass.

Reply to
Archimedes' Lever

Fleas and lice are smaller. Some have even invaded this group unseen by most.

Reply to
Archimedes' Lever

Damn! The little bastard actually said something quite intelligent!

I am impressed... really.

Reply to
DarkMatter

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