What are 6.5 Digit Multimeters Good For?

D from BC schrieb:

Of course there's always something better..
8.5 Digit multimeter

Hello,

if you carefully read the specifications of some 8.5 Digit multimeter,
you will find out that you get the full performance only up to one day
after calibration, at 20 +- 1 °C and only when measuring DC voltages
between 1 and 10 V. ;-)

Bye

D from BC schrieb:

Of course there's always something better..
8.5 Digit multimeter

Hello,

if you carefully read the specifications of some 8.5 Digit multimeter,
you will find out that you get the full performance only up to one day
after calibration, at 20 +- 1 °C and only when measuring DC voltages
between 1 and 10 V. ;-)

Bye

On Thu, 11 Mar 2010 23:25:31 -0600, Jim Yanik <jyanik_at_abuse.gov> wrote:

D from BC <myrealaddress_at_comic.com> wrote in
news:MPG.26034c831878edc69896e6_at_209.197.12.12:

In article <a69jp59q5nvmomn6rqobm4q4a3m0a4088k_at_4ax.com>,
jjlarkin_at_highNOTlandTHIStechnologyPART.com says...

On Thu, 11 Mar 2010 17:56:35 -0800, D from BC
myrealaddress_at_comic.com> wrote:

6.5 digit multimeters sell around $1000.00.
For electronics development, are these $1000 multimeters really
necessary?
What are they good for?

Measuring to PPM accuracy, and measuring microvolt-level voltages. And
as a traceable standard for calibrating products.

and they generally have better AC volt accuracies.


The Fluke 8845A is excellent.

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


John

Ah.. the tool that sets the tools.

Of course there's always something better..
8.5 Digit multimeter
http://www.home.agilent.com/agilent/product.jspx?nid=-
536902435.536881781.00&cc=US&lc=eng


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

Which is why Keithley is better.

On a sunny day (Thu, 11 Mar 2010 17:56:35 -0800) it happened D from BC
myrealaddress_at_comic.com> wrote in <MPG.26033f321480b139896e5_at_209.197.12.12>:

6.5 digit multimeters sell around $1000.00.
For electronics development, are these $1000 multimeters really
necessary?
What are they good for?

They are not needed, all you need is a 5 Euro multimeter,
and in extreme cases a precise reference.
That means if you use one of those reference chips, you borrow
the very accurate multimeter for a day, measure your reference chip,
write it down, and use that to calibrate your cheap multimeter,
or o compute it's real value,
Saved: 1000$

On a sunny day (Thu, 11 Mar 2010 17:56:35 -0800) it happened D from BC
myrealaddress_at_comic.com> wrote in <MPG.26033f321480b139896e5_at_209.197.12.12>:

6.5 digit multimeters sell around $1000.00.
For electronics development, are these $1000 multimeters really
necessary?

What are they good for?

They are not needed, all you need is a 5 Euro multimeter,
and in extreme cases a precise reference.
That means if you use one of those reference chips, you borrow
the very accurate multimeter for a day, measure your reference chip,
write it down, and use that to calibrate your cheap multimeter,
or o compute it's real value,
Saved: 1000$

Of course there are exceptions,
but in places where that counts they usually have a lot of ++++expensive stuff anyways.
Usually places where nothing really useful is done, like in CERN, or ITER, or LIGO,
etc.

On a sunny day (Thu, 11 Mar 2010 17:56:35 -0800) it happened D from BC
myrealaddress_at_comic.com> wrote in <MPG.26033f321480b139896e5_at_209.197.12.12>:

6.5 digit multimeters sell around $1000.00.
For electronics development, are these $1000 multimeters really
necessary?
What are they good for?

They are not needed, all you need is a 5 Euro multimeter,
and in extreme cases a precise reference.

On Thu, 11 Mar 2010 17:56:35 -0800, the renowned D from BC
myrealaddress_at_comic.com> wrote:

6.5 digit multimeters sell around $1000.00.
For electronics development, are these $1000 multimeters really
necessary?
What are they good for?

If you're developing precise instruments, you would prefer to have
test equipment that has higher (preferably MUCH higher) performance
than the devices you are developing. Say you have designed a 0.1% or
0.01% current source for a sensor and want to confirm how much it
drifts with temperature within 1%.

It's not as easy when you approach or pass the limits of what has been
done (or what you can afford to buy/rent/borrow) and you have figure
out how the heck to test it.

I don't see how a meter like that would be all that useful if you were
only developing digital, audio or RF though.


Best regards,
Spehro Pefhany

On a sunny day (Thu, 11 Mar 2010 17:56:35 -0800) it happened D from BC
myrealaddress_at_comic.com> wrote in <MPG.26033f321480b139896e5_at_209.197.12.12>:

6.5 digit multimeters sell around $1000.00.
For electronics development, are these $1000 multimeters really
necessary?
What are they good for?

They are not needed, all you need is a 5 Euro multimeter,
and in extreme cases a precise reference.
That means if you use one of those reference chips, you borrow
the very accurate multimeter for a day, measure your reference chip,
write it down, and use that to calibrate your cheap multimeter,
or o compute it's real value,
Saved: 1000$

Of course there are exceptions,
but in places where that counts they usually have a lot of ++++expensive stuff anyways.
Usually places where nothing really useful is done, like in CERN, or ITER, or LIGO,
etc.

In article <hndc5b$37k$1_at_news.albasani.net>, pNaonStpealmtje_at_yahoo.com
says...

On a sunny day (Thu, 11 Mar 2010 17:56:35 -0800) it happened D from BC
myrealaddress_at_comic.com> wrote in <MPG.26033f321480b139896e5_at_209.197.12.12>:

6.5 digit multimeters sell around $1000.00.
For electronics development, are these $1000 multimeters really
necessary?
What are they good for?

They are not needed, all you need is a 5 Euro multimeter,
and in extreme cases a precise reference.
That means if you use one of those reference chips, you borrow
the very accurate multimeter for a day, measure your reference chip,
write it down, and use that to calibrate your cheap multimeter,
or o compute it's real value,
Saved: 1000$

Of course there are exceptions,
but in places where that counts they usually have a lot of ++++expensive stuff anyways.
Usually places where nothing really useful is done, like in CERN, or ITER, or LIGO,
etc.

How about mohm measurements? Maybe that's handy.
My DMM only goes to 0.1 ohm.
I thought of measuring DCR of coils or pcb trace resistance for sim
accuracy.

On Mar 12, 12:33 pm, D from BC <myrealaddr...@comic.com> wrote:
In article <hndc5b$37...@news.albasani.net>, pNaonStpealm...@yahoo.com
says...





On a sunny day (Thu, 11 Mar 2010 17:56:35 -0800) it happened D from BC
myrealaddr...@comic.com> wrote in <MPG.26033f321480b13989...@209.197.12.12>:

6.5 digit multimeters sell around $1000.00.
For electronics development, are these $1000 multimeters really
necessary?
What are they good for?

They are not needed, all you need is a 5 Euro multimeter,
and in extreme cases a precise reference.
That means if you use one of those reference chips, you borrow
the very accurate multimeter for a day, measure your reference chip,
write it down, and use that to calibrate your cheap multimeter,
or o compute it's real value,
Saved: 1000$

Of course there are exceptions,
but in places where that counts they usually have a lot of ++++expensive stuff anyways.
Usually places where nothing really useful is done, like in CERN, or ITER, or LIGO,
etc.

How about mohm measurements? Maybe that's handy.
My DMM only goes to 0.1 ohm.
I thought of measuring DCR of coils or pcb trace resistance for sim
accuracy.

One use is to find shorts on circuit boards. The really accurate
resistance measurement lets you home in on the offending part

It's interesting to calculate the resistance of traces and actually
measure them. Most pcb houses skimp on plating, so when you specify "1
oz" copper, you seldom get it.

In article <hndc5b$37...@news.albasani.net>, pNaonStpealm...@yahoo.com
says...





On a sunny day (Thu, 11 Mar 2010 17:56:35 -0800) it happened D from BC
myrealaddr...@comic.com> wrote in <MPG.26033f321480b13989...@209.197.12.12>:

6.5 digit multimeters sell around $1000.00.
For electronics development, are these $1000 multimeters really
necessary?
What are they good for?

They are not needed, all you need is a 5 Euro multimeter,
and in extreme cases a precise reference.
That means if you use one of those reference chips, you borrow
the very accurate multimeter for a day, measure your reference chip,
write it down, and use that to calibrate your cheap multimeter,
or o compute it's real value,
Saved: 1000$

Of course there are exceptions,
but in places where that counts they usually have a lot of ++++expensive stuff anyways.
Usually places where nothing really useful is done, like in CERN, or ITER, or LIGO,
etc.

How about mohm measurements? Maybe that's handy.
My DMM only goes to 0.1 ohm.
I thought of measuring DCR of coils or pcb trace resistance for sim
accuracy.

In article <hndc5b$37k$1_at_news.albasani.net>, pNaonStpealmtje_at_yahoo.com
says...

On a sunny day (Thu, 11 Mar 2010 17:56:35 -0800) it happened D from BC
myrealaddress_at_comic.com> wrote in <MPG.26033f321480b139896e5_at_209.197.12.12>:

6.5 digit multimeters sell around $1000.00.
For electronics development, are these $1000 multimeters really
necessary?
What are they good for?

They are not needed, all you need is a 5 Euro multimeter,
and in extreme cases a precise reference.
That means if you use one of those reference chips, you borrow
the very accurate multimeter for a day, measure your reference chip,
write it down, and use that to calibrate your cheap multimeter,
or o compute it's real value,
Saved: 1000$

Of course there are exceptions,
but in places where that counts they usually have a lot of ++++expensive stuff anyways.
Usually places where nothing really useful is done, like in CERN, or ITER, or LIGO,
etc.

How about mohm measurements? Maybe that's handy.
My DMM only goes to 0.1 ohm.
I thought of measuring DCR of coils or pcb trace resistance for sim
accuracy.

On Fri, 12 Mar 2010 12:30:31 GMT, Jan Panteltje
pNaonStpealmtje_at_yahoo.com> wrote:

On a sunny day (Thu, 11 Mar 2010 17:56:35 -0800) it happened D from BC
myrealaddress_at_comic.com> wrote in <MPG.26033f321480b139896e5_at_209.197.12.12>:

6.5 digit multimeters sell around $1000.00.
For electronics development, are these $1000 multimeters really
necessary?
What are they good for?

They are not needed, all you need is a 5 Euro multimeter,
and in extreme cases a precise reference.

Does your e5 multimeter resolve microvolts? If not, it's useless for
designing thermocouple stuff.

Can it measure resistance to 0.02%? That
is useful too.

If all you do is muck around with uPs that have 8 bit ADCs, a cheap
meter is almost good enough.

One cool thing to do with a good DVM is measure voltage drops in PCB
traces and planes, often microvolts. That answers the eternal
question. "where is the damned current going?"

John