On Wed, 07 Mar 2007 06:25:48 GMT, Robert Baer
Gave us:


I gave up responding to him a while back as being a useless waste of
time.

Ahh... so you're a double posting dope too!

This dope is still running windows 98!

On Wed, 7 Mar 2007 02:45:32 -0600, "Anthony Fremont"
Gave us:

Anthony Fremont wrote:

50nA you idiot. DO THE MATH!

BTW, I'm surprised you didn't have anything to say about my Extech/Micronta
Shootout thread? I did some resistance measurements and the Micronta is
right on with way less than 1% difference. Drifted to another plane, ha ha
ha 15 years old and still within 1% on most functions. HA HA HA HA Wrong
again DM.


How would you know without a reliable device to check it against,
dip****?

I'll clue you... the extech ain't it.

Bwuahahahahahaahah!

MassiveProng wrote:
On Wed, 7 Mar 2007 02:45:32 -0600, "Anthony Fremont"
Gave us:

Anthony Fremont wrote:

50nA you idiot. DO THE MATH!

BTW, I'm surprised you didn't have anything to say about my
Extech/Micronta Shootout thread? I did some resistance measurements
and the Micronta is right on with way less than 1% difference.
Drifted to another plane, ha ha ha 15 years old and still within
1% on most functions. HA HA HA HA Wrong again DM.


How would you know without a reliable device to check it against,
dip****?

I'll clue you... the extech ain't it.

Bwuahahahahahaahah!

Oh really? And just how do you figure that? It's brand new and it was
available with an NIST certificate (though I didn't opt for it). I guess I
need to send it to you so you can verify it against your Protek?

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accumulation place.
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We are a big agent for Laptop
Mobile Phone\Digital Camera\CDJ\DJM\Apple Ipod\PSP\VEDEO GAMES
\Television\GPS\Telescope in CHINA .
All of our commodities is the most advanced quality but lowest price.
we also have the

safest and most
convenient transaction way to guarante the transaction arries on
normally .
looking forward to your coorporation and cause all of us both to
profit.
you can contact us by Email:china.seller#hotmail.com
MSN: china.seller#hotmail.com
best wishes!
your sincerely

http://www.china-powerseller.com
MSN/Email:

On Wed, 7 Mar 2007 07:06:35 -0600, "Anthony Fremont"
Gave us:

MassiveProng wrote:
On Wed, 7 Mar 2007 02:45:32 -0600, "Anthony Fremont"
Gave us:

Anthony Fremont wrote:

50nA you idiot. DO THE MATH!

BTW, I'm surprised you didn't have anything to say about my
Extech/Micronta Shootout thread? I did some resistance measurements
and the Micronta is right on with way less than 1% difference.
Drifted to another plane, ha ha ha 15 years old and still within
1% on most functions. HA HA HA HA Wrong again DM.


How would you know without a reliable device to check it against,
dip****?

I'll clue you... the extech ain't it.

Bwuahahahahahaahah!

Oh really? And just how do you figure that? It's brand new and it was
available with an NIST certificate (though I didn't opt for it). I guess I
need to send it to you so you can verify it against your Protek?

I told you, dumbass, I have a calibrated HP 3478A.

The protek is ANOTHER meter I have, and I use the HP to verify it.

Your NON NIST traceable and certified Extech is calibrated by an
assembler that was working enough years to end up in the production
test lab.

Their prime pass yields are likely far less than 90%, and 96% is
considered poor. Yes, you'll have to look that one up.

I'll say it again...


Bwuahahahahahahaha!

MassiveProng wrote:
On Wed, 7 Mar 2007 07:06:35 -0600, "Anthony Fremont"
Gave us:

MassiveProng wrote:
On Wed, 7 Mar 2007 02:45:32 -0600, "Anthony Fremont"
Gave us:

Anthony Fremont wrote:

50nA you idiot. DO THE MATH!

BTW, I'm surprised you didn't have anything to say about my
Extech/Micronta Shootout thread? I did some resistance
measurements and the Micronta is right on with way less than 1%
difference. Drifted to another plane, ha ha ha 15 years old and
still within 1% on most functions. HA HA HA HA Wrong again DM.


How would you know without a reliable device to check it against,
dip****?

I'll clue you... the extech ain't it.

Bwuahahahahahaahah!

Oh really? And just how do you figure that? It's brand new and it
was available with an NIST certificate (though I didn't opt for it).
I guess I need to send it to you so you can verify it against your
Protek?

I told you, dumbass, I have a calibrated HP 3478A.

The protek is ANOTHER meter I have, and I use the HP to verify it.

Your NON NIST traceable and certified Extech is calibrated by an
assembler that was working enough years to end up in the production
test lab.

At least you didn't touch it.

Their prime pass yields are likely far less than 90%, and 96% is
considered poor. Yes, you'll have to look that one up.

I'll say it again...


Bwuahahahahahahaha!

Funny how it can be sent in and certified after the sale. I wonder how they
know who to send the good ones to. These meters you have at home, what do
you use them for? I mean I never see a schematic from you or hear of you
tinkering with some kind of experiment. Why is that?

On Wed, 7 Mar 2007 20:27:58 -0600, "Anthony Fremont"
Gave us:

Funny how it can be sent in and certified after the sale.


Anything can, you ****in' retard.

On Mar 8, 10:57 am, MassiveProng
wrote:
On Wed, 7 Mar 2007 07:06:35 -0600, "Anthony Fremont"
Gave us:



MassiveProng wrote:
On Wed, 7 Mar 2007 02:45:32 -0600, "Anthony Fremont"
Gave us:

Anthony Fremont wrote:

50nA you idiot. DO THE MATH!

BTW, I'm surprised you didn't have anything to say about my
Extech/Micronta Shootout thread? I did some resistance measurements
and the Micronta is right on with way less than 1% difference.
Drifted to another plane, ha ha ha 15 years old and still within
1% on most functions. HA HA HA HA Wrong again DM.

How would you know without a reliable device to check it against,
dip****?

I'll clue you... the extech ain't it.

Bwuahahahahahaahah!

Oh really? And just how do you figure that? It's brand new and it was
available with an NIST certificate (though I didn't opt for it). I guess I
need to send it to you so you can verify it against your Protek?

I told you, dumbass, I have a calibrated HP 3478A.

The protek is ANOTHER meter I have, and I use the HP to verify it.

You don't even know when you are being made fun of!

Your NON NIST traceable and certified Extech is calibrated by an
assembler that was working enough years to end up in the production
test lab.

At this price and accuracy level it is almost certain that every unit
would be automatically factory tested to be in-spec, so the NIST cert
is worth the paper it's written on. You can bet the farm that
Anthony's new meter meets the published specs.

Dave

On 8 Mar 2007 01:02:52 -0800, "David L. Jones"
Gave us:

At this price and accuracy level it is almost certain that every unit
would be automatically factory tested to be in-spec, so the NIST cert
is worth the paper it's written on. You can bet the farm that
Anthony's new meter meets the published specs.


Idiot! His meter is NOT certified. Learn to read.

MassiveProng wrote:
On 8 Mar 2007 01:02:52 -0800, "David L. Jones"
Gave us:

At this price and accuracy level it is almost certain that every unit
would be automatically factory tested to be in-spec, so the NIST cert
is worth the paper it's written on. You can bet the farm that
Anthony's new meter meets the published specs.


Idiot! His meter is NOT certified. Learn to read.

It comes with specs, they always apply. Wasn't it you that said that certs
were often just a check not necessarily turning screws? If the meter said
Agilent or Fluke on it, would you even be mentioning this? How come you
didn't say anything about the RMS convertor behaving the way I described? I
thought you were knowledgeable on this stuff.

"Anthony Fremont" wrote in
:

MassiveProng wrote:
On 8 Mar 2007 01:02:52 -0800, "David L. Jones"
Gave us:

At this price and accuracy level it is almost certain that every
unit would be automatically factory tested to be in-spec, so the
NIST cert is worth the paper it's written on. You can bet the farm
that Anthony's new meter meets the published specs.


Idiot! His meter is NOT certified. Learn to read.

It comes with specs, they always apply. Wasn't it you that said that
certs were often just a check not necessarily turning screws? If the
meter said Agilent or Fluke on it, would you even be mentioning this?
How come you didn't say anything about the RMS convertor behaving the
way I described? I thought you were knowledgeable on this stuff.




Cal Certificates just state the instrument was calibrated using known
standards traceable to NIST,the date the work was done,temp and humidity
conditions,and the recommended cal interval.They may list the standards
used and their expiration dates.

--
Jim Yanik
jyanik
at
kua.net

Finding the keyboard operational
MassiveProng entered:

On 8 Mar 2007 01:02:52 -0800, "David L. Jones"
Gave us:

At this price and accuracy level it is almost certain that every unit
would be automatically factory tested to be in-spec, so the NIST cert
is worth the paper it's written on. You can bet the farm that
Anthony's new meter meets the published specs.


Idiot! His meter is NOT certified. Learn to read.

Youu do realize that calibrated and certified are not the same thing, don't
you? You could have your HP 3478A certified to +/- 10% VDC.
Bob
--�
--�
Coffee worth staying up for - NY Times
www.moondoggiecoffee.com

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accumulation place.
The website of our company is http://www.china-powerseller.com
We are a big agent for Laptop
Mobile Phone\Digital Camera\CDJ\DJM\Apple Ipod\PSP\VEDEO GAMES
\Television\GPS\Telescope in CHINA .
All of our commodities is the most advanced quality but lowest price.
we also have the

safest and most
convenient transaction way to guarante the transaction arries on
normally .
looking forward to your coorporation and cause all of us both to
profit.
you can contact us by Email:china.seller#hotmail.com
MSN: china.seller#hotmail.com
best wishes!
your sincerely

http://www.china-powerseller.com
MSN/Email:

Jim Yanik wrote:
After reading all this,I checked the $3 DMM I bought at a Harbor Freight
sidewalk sale,and it turns out the *input Z is only ONE megohm*. YUK!

My first meter cost five times that, was analog, and only had 20K ohms
per volt.

For those young folk who aren't familiar with that, yes, the meter input
impedance changed depending on the range you set the meter to.

--
Martians drive SUVs! http://oregonmag.com/MarsWarm307.html

clifto wrote:
Jim Yanik wrote:
After reading all this,I checked the $3 DMM I bought at a Harbor
Freight sidewalk sale,and it turns out the *input Z is only ONE
megohm*. YUK!

My first meter cost five times that, was analog, and only had 20K ohms
per volt.

For those young folk who aren't familiar with that, yes, the meter
input impedance changed depending on the range you set the meter to.

My first meter (a cheapie my dad's friend gave me when I was about 10) was
in that range (could it have been 10k?). The better meters I had in my
younger days were a whopping 50k ohms/volt.

clifto wrote:
Jim Yanik wrote:

After reading all this,I checked the $3 DMM I bought at a Harbor Freight
sidewalk sale,and it turns out the *input Z is only ONE megohm*. YUK!


My first meter cost five times that, was analog, and only had 20K ohms
per volt.

For those young folk who aren't familiar with that, yes, the meter input
impedance changed depending on the range you set the meter to.

Check; the neatthing is that on higher voltage scales, the input
resistance exceeds that of a DMM.
Which is why i built a voltmeter/currentmeter around a 5 microamp
movement giving 200K per volt sensitivity.

Anthony Fremont wrote:

clifto wrote:

Jim Yanik wrote:

After reading all this,I checked the $3 DMM I bought at a Harbor
Freight sidewalk sale,and it turns out the *input Z is only ONE
megohm*. YUK!

My first meter cost five times that, was analog, and only had 20K ohms
per volt.

For those young folk who aren't familiar with that, yes, the meter
input impedance changed depending on the range you set the meter to.


My first meter (a cheapie my dad's friend gave me when I was about 10) was
in that range (could it have been 10k?). The better meters I had in my
younger days were a whopping 50k ohms/volt.


I do remember seeing one of those 50K/V meters whan i was young; what
the heck has happened to them?

"clifto" wrote in message
...

My first meter cost five times that, was analog, and only had 20K ohms
per volt.

Mine was 2K IIRC. I still have it.

Robert Baer wrote:
Anthony Fremont wrote:

clifto wrote:

Jim Yanik wrote:

After reading all this,I checked the $3 DMM I bought at a Harbor
Freight sidewalk sale,and it turns out the *input Z is only ONE
megohm*. YUK!

My first meter cost five times that, was analog, and only had 20K
ohms per volt.

For those young folk who aren't familiar with that, yes, the meter
input impedance changed depending on the range you set the meter to.


My first meter (a cheapie my dad's friend gave me when I was about
10) was in that range (could it have been 10k?). The better meters
I had in my younger days were a whopping 50k ohms/volt.


I do remember seeing one of those 50K/V meters whan i was young;
what the heck has happened to them?

Here's a couple of beauts:
http://www.bkprecision.com/www/np_se...og+Multimeters

Robert Baer wrote in
news
clifto wrote:
Jim Yanik wrote:

After reading all this,I checked the $3 DMM I bought at a Harbor
Freight sidewalk sale,and it turns out the *input Z is only ONE
megohm*. YUK!


My first meter cost five times that, was analog, and only had 20K
ohms per volt.

For those young folk who aren't familiar with that, yes, the meter
input impedance changed depending on the range you set the meter to.

Check; the neatthing is that on higher voltage scales, the input
resistance exceeds that of a DMM.
Which is why i built a voltmeter/currentmeter around a 5 microamp
movement giving 200K per volt sensitivity.


Then there's the Fluke differential voltmeters,that have nearly infinite
impedance at null. ISTR a HP diff VM that had a 100Meg Z on it's off-null
mode.Then there are Keithley hi-Z meters,with gigohm input Zs.

--
Jim Yanik
jyanik
at
kua.net

Anthony Fremont wrote:
Robert Baer wrote:

Anthony Fremont wrote:


clifto wrote:


Jim Yanik wrote:


After reading all this,I checked the $3 DMM I bought at a Harbor
Freight sidewalk sale,and it turns out the *input Z is only ONE
megohm*. YUK!

My first meter cost five times that, was analog, and only had 20K
ohms per volt.

For those young folk who aren't familiar with that, yes, the meter
input impedance changed depending on the range you set the meter to.


My first meter (a cheapie my dad's friend gave me when I was about
10) was in that range (could it have been 10k?). The better meters
I had in my younger days were a whopping 50k ohms/volt.



I do remember seeing one of those 50K/V meters whan i was young;
what the heck has happened to them?


Here's a couple of beauts:
http://www.bkprecision.com/www/np_se...og+Multimeters




That 114B is the best one..

Jim Yanik wrote:

Robert Baer wrote in
news

clifto wrote:

Jim Yanik wrote:


After reading all this,I checked the $3 DMM I bought at a Harbor
Freight sidewalk sale,and it turns out the *input Z is only ONE
megohm*. YUK!


My first meter cost five times that, was analog, and only had 20K
ohms per volt.

For those young folk who aren't familiar with that, yes, the meter
input impedance changed depending on the range you set the meter to.


Check; the neatthing is that on higher voltage scales, the input
resistance exceeds that of a DMM.
Which is why i built a voltmeter/currentmeter around a 5 microamp
movement giving 200K per volt sensitivity.



Then there's the Fluke differential voltmeters,that have nearly infinite
impedance at null. ISTR a HP diff VM that had a 100Meg Z on it's off-null
mode.Then there are Keithley hi-Z meters,with gigohm input Zs.

Wouldn't be neat to have a handheld differential voltmeter?

On Thu, 8 Mar 2007 07:24:18 -0600, "Anthony Fremont"
Gave us:

Wasn't it you that said that certs
were often just a check not necessarily turning screws?

NO! I said that when you get your gear calibrated, it is typically
ONLY a verification of a good instrument.

Being off cal usually means something is awry.

What you are paying for is a VERY nice standard and a comparison
check against it. Of the hundreds of calibration sessions that we
have had done IN our lab, as opposed to sending the gear out, it was
done without them ever opening a single instrument.

On Thu, 08 Mar 2007 13:34:45 -0600, clifto Gave us:

My first meter cost five times that, was analog, and only had 20K ohms
per volt.

For those young folk who aren't familiar with that, yes, the meter input
impedance changed depending on the range you set the meter to.


Lemmie guess... An RCA Master Volt Ohmist?

I still have one of those as well.

Have a couple Heathkit MMs around too.

MassiveProng wrote:
On Thu, 8 Mar 2007 07:24:18 -0600, "Anthony Fremont"
Gave us:

Wasn't it you that said that certs
were often just a check not necessarily turning screws?

NO! I said that when you get your gear calibrated, it is typically
ONLY a verification of a good instrument.

Pretty close to the same thing to me.

Being off cal usually means something is awry.

What you are paying for is a VERY nice standard and a comparison
check against it. Of the hundreds of calibration sessions that we
have had done IN our lab, as opposed to sending the gear out, it was
done without them ever opening a single instrument.

IOW you didn't turn any screws, you just checked it.

Robert Baer wrote:
Anthony Fremont wrote:

Here's a couple of beauts:
http://www.bkprecision.com/www/np_se...og+Multimeters




That 114B is the best one..

Yeah, but it's not as good looking as the other one though. I just recently
saw another really nice, big analog meter that someone sells. It wasn't
cheap either, but I can't recall where I saw it. I was thinking it was in
my Jameco catalog, but I can't seem to find it in there. It looked allot
like the older ones.

On Thu, 8 Mar 2007 20:10:09 -0600, "Anthony Fremont"
Gave us:

MassiveProng wrote:
On Thu, 8 Mar 2007 07:24:18 -0600, "Anthony Fremont"
Gave us:

Wasn't it you that said that certs
were often just a check not necessarily turning screws?

NO! I said that when you get your gear calibrated, it is typically
ONLY a verification of a good instrument.

Pretty close to the same thing to me.

Being off cal usually means something is awry.

What you are paying for is a VERY nice standard and a comparison
check against it. Of the hundreds of calibration sessions that we
have had done IN our lab, as opposed to sending the gear out, it was
done without them ever opening a single instrument.

IOW you didn't turn any screws, you just checked it.

That is 99.999% of the time ALL they do.

That would be worldwide practice.

Robert Baer wrote in
link.net:

Jim Yanik wrote:

Robert Baer wrote in
news

clifto wrote:

Jim Yanik wrote:


After reading all this,I checked the $3 DMM I bought at a Harbor
Freight sidewalk sale,and it turns out the *input Z is only ONE
megohm*. YUK!


My first meter cost five times that, was analog, and only had 20K
ohms per volt.

For those young folk who aren't familiar with that, yes, the meter
input impedance changed depending on the range you set the meter to.


Check; the neatthing is that on higher voltage scales, the input
resistance exceeds that of a DMM.
Which is why i built a voltmeter/currentmeter around a 5 microamp
movement giving 200K per volt sensitivity.



Then there's the Fluke differential voltmeters,that have nearly
infinite impedance at null. ISTR a HP diff VM that had a 100Meg Z on
it's off-null mode.Then there are Keithley hi-Z meters,with gigohm
input Zs.

Wouldn't be neat to have a handheld differential voltmeter?


why do you need that accuracy in a handheld instrument?


--
Jim Yanik
jyanik
at
kua.net

"Anthony Fremont" wrote in
:

MassiveProng wrote:
On Thu, 8 Mar 2007 07:24:18 -0600, "Anthony Fremont"
Gave us:

Wasn't it you that said that certs
were often just a check not necessarily turning screws?

NO! I said that when you get your gear calibrated, it is typically
ONLY a verification of a good instrument.

Pretty close to the same thing to me.

Being off cal usually means something is awry.

What you are paying for is a VERY nice standard

I would say "accurate,traceable standard".

and a comparison
check against it. Of the hundreds of calibration sessions that we
have had done IN our lab, as opposed to sending the gear out, it was
done without them ever opening a single instrument.

IOW you didn't turn any screws, you just checked it.




If it meets all specs,then there is no need for adjustment.

In fact,you might make it worse by tweaking on adjustments.
(some pots or trim caps on older instruments freeze in place and turning
them breaks them or they become noisy)

Instruments that have been adjusted have to be rechecked,as some
adjustments interact with others.Trying to "optimize" a range may throw
another range or ranges out of spec.

--
Jim Yanik
jyanik
at
kua.net

Jim Yanik wrote:
Robert Baer wrote in
link.net:

Jim Yanik wrote:

Robert Baer wrote in
news

clifto wrote:

Jim Yanik wrote:


After reading all this,I checked the $3 DMM I bought at a Harbor
Freight sidewalk sale,and it turns out the *input Z is only ONE
megohm*. YUK!


My first meter cost five times that, was analog, and only had 20K
ohms per volt.

For those young folk who aren't familiar with that, yes, the meter
input impedance changed depending on the range you set the meter to.


Check; the neatthing is that on higher voltage scales, the input
resistance exceeds that of a DMM.
Which is why i built a voltmeter/currentmeter around a 5 microamp
movement giving 200K per volt sensitivity.



Then there's the Fluke differential voltmeters,that have nearly
infinite impedance at null. ISTR a HP diff VM that had a 100Meg Z on
it's off-null mode.Then there are Keithley hi-Z meters,with gigohm
input Zs.

Wouldn't be neat to have a handheld differential voltmeter?


why do you need that accuracy in a handheld instrument?

I don't *need* a Ferrari, but it would be neat to have one.

--
Martians drive SUVs! http://oregonmag.com/MarsWarm307.html

On 9 Mar 2007 17:24:20 GMT, Jim Yanik Gave us:

"Anthony Fremont" wrote in
:

MassiveProng wrote:
On Thu, 8 Mar 2007 07:24:18 -0600, "Anthony Fremont"
Gave us:

Wasn't it you that said that certs
were often just a check not necessarily turning screws?

NO! I said that when you get your gear calibrated, it is typically
ONLY a verification of a good instrument.

Pretty close to the same thing to me.

Being off cal usually means something is awry.

What you are paying for is a VERY nice standard

I would say "accurate,traceable standard".

and a comparison
check against it. Of the hundreds of calibration sessions that we
have had done IN our lab, as opposed to sending the gear out, it was
done without them ever opening a single instrument.

IOW you didn't turn any screws, you just checked it.




If it meets all specs,then there is no need for adjustment.

In fact,you might make it worse by tweaking on adjustments.
(some pots or trim caps on older instruments freeze in place and turning
them breaks them or they become noisy)

Instruments that have been adjusted have to be rechecked,as some
adjustments interact with others.Trying to "optimize" a range may throw
another range or ranges out of spec.


All great reasons to abide 100% with my original reply.

So there, Too Much Toolessness!, you ****ing RETARD!.

clifto wrote in :

Jim Yanik wrote:
Robert Baer wrote in
link.net:

Jim Yanik wrote:

Robert Baer wrote in
news

clifto wrote:

Jim Yanik wrote:


After reading all this,I checked the $3 DMM I bought at a Harbor
Freight sidewalk sale,and it turns out the *input Z is only ONE
megohm*. YUK!


My first meter cost five times that, was analog, and only had 20K
ohms per volt.

For those young folk who aren't familiar with that, yes, the meter
input impedance changed depending on the range you set the meter to.


Check; the neatthing is that on higher voltage scales, the input
resistance exceeds that of a DMM.
Which is why i built a voltmeter/currentmeter around a 5 microamp
movement giving 200K per volt sensitivity.



Then there's the Fluke differential voltmeters,that have nearly
infinite impedance at null. ISTR a HP diff VM that had a 100Meg Z on
it's off-null mode.Then there are Keithley hi-Z meters,with gigohm
input Zs.

Wouldn't be neat to have a handheld differential voltmeter?


why do you need that accuracy in a handheld instrument?

I don't *need* a Ferrari, but it would be neat to have one.


well,precision lab instruments are used in lab conditions,with at least 15
minute warmup times to allow the unit to stabilize,and to expect that
accuracy in a handheld that would be used in non-lab conditions....it
doesn't make sense.

BTW,when calibrating precision instruments,the unit under test has to warm
up and stabilize for 20 minutes minimum,and the lab has a controlled
temperature and humidity,usually 73+/-2 degF. Of course,your lab standards
have already been powered up and stabilized for the proper time.
Insturments used outside of specified temps were derated in accuracy.

I worked in a USAF depot-level primary standards lab.(PMEL)
(before repairing and calibrating for Tektronix for 21.5 yrs.)
My lab (L.G. Hanscom Fld) did the MIT-Lincoln Labs instruments,besides the
usual USAF stuff,covered Pease,Otis,and other military bases.

--
Jim Yanik
jyanik
at
kua.net

Jim Yanik wrote:

Robert Baer wrote in
link.net:


Jim Yanik wrote:


Robert Baer wrote in
news


clifto wrote:


Jim Yanik wrote:



After reading all this,I checked the $3 DMM I bought at a Harbor
Freight sidewalk sale,and it turns out the *input Z is only ONE
megohm*. YUK!


My first meter cost five times that, was analog, and only had 20K
ohms per volt.

For those young folk who aren't familiar with that, yes, the meter
input impedance changed depending on the range you set the meter to.


Check; the neatthing is that on higher voltage scales, the input
resistance exceeds that of a DMM.
Which is why i built a voltmeter/currentmeter around a 5 microamp
movement giving 200K per volt sensitivity.



Then there's the Fluke differential voltmeters,that have nearly
infinite impedance at null. ISTR a HP diff VM that had a 100Meg Z on
it's off-null mode.Then there are Keithley hi-Z meters,with gigohm
input Zs.


Wouldn't be neat to have a handheld differential voltmeter?



why do you need that accuracy in a handheld instrument?


Someone asked the same question about a pocket scope.
I guess there are times and conditions when such "esoteric" equipment
would be nice to have.

MassiveProng wrote:
On Thu, 8 Mar 2007 07:24:18 -0600, "Anthony Fremont"
Gave us:

Wasn't it you that said that certs
were often just a check not necessarily turning screws?

NO! I said that when you get your gear calibrated, it is typically
ONLY a verification of a good instrument.

Being off cal usually means something is awry.

What you are paying for is a VERY nice standard and a comparison
check against it. Of the hundreds of calibration sessions that we
have had done IN our lab, as opposed to sending the gear out, it was
done without them ever opening a single instrument.
-
Odd, I've been working in a cal lab for the last few years, and I'd say
a good 10% of what we get has something wrong with it. Some of it is
designed-in problems, but most of the rest is due to impact damage or
contamination. Our customers are largely the petrochemical industries
along the Gulf Coast, and they apparently believe that if a piece of
gear can't survive a 1 meter fall onto concrete, or being rained on and
rattling around in the back of a pickup truck for a few weeks, than
there's obviously something wrong with it anyway. It makes for a good
business in replacing switching, connectors and cracked LCDs.

On Sat, 10 Mar 2007 08:41:44 GMT, Robert Baer
Gave us:

Jim Yanik wrote:

Robert Baer wrote in
link.net:


Jim Yanik wrote:


Robert Baer wrote in
news


clifto wrote:


Jim Yanik wrote:



After reading all this,I checked the $3 DMM I bought at a Harbor
Freight sidewalk sale,and it turns out the *input Z is only ONE
megohm*. YUK!


My first meter cost five times that, was analog, and only had 20K
ohms per volt.

For those young folk who aren't familiar with that, yes, the meter
input impedance changed depending on the range you set the meter to.


Check; the neatthing is that on higher voltage scales, the input
resistance exceeds that of a DMM.
Which is why i built a voltmeter/currentmeter around a 5 microamp
movement giving 200K per volt sensitivity.



Then there's the Fluke differential voltmeters,that have nearly
infinite impedance at null. ISTR a HP diff VM that had a 100Meg Z on
it's off-null mode.Then there are Keithley hi-Z meters,with gigohm
input Zs.


Wouldn't be neat to have a handheld differential voltmeter?



why do you need that accuracy in a handheld instrument?


Someone asked the same question about a pocket scope.
I guess there are times and conditions when such "esoteric" equipment
would be nice to have.


Ahhhh... the "nice" factor.

I think it would be nice to have a nice Agilent spectrum analyser,
or network analyser, but I don't have $60+k for each right now.

Maybe after I win the lottery.

On Sat, 10 Mar 2007 10:38:04 -0600, Palinurus
Gave us:

MassiveProng wrote:
On Thu, 8 Mar 2007 07:24:18 -0600, "Anthony Fremont"
Gave us:

Wasn't it you that said that certs
were often just a check not necessarily turning screws?

NO! I said that when you get your gear calibrated, it is typically
ONLY a verification of a good instrument.

Being off cal usually means something is awry.

What you are paying for is a VERY nice standard and a comparison
check against it. Of the hundreds of calibration sessions that we
have had done IN our lab, as opposed to sending the gear out, it was
done without them ever opening a single instrument.
-
Odd, I've been working in a cal lab for the last few years, and I'd say
a good 10% of what we get has something wrong with it. Some of it is
designed-in problems, but most of the rest is due to impact damage or
contamination. Our customers are largely the petrochemical industries
along the Gulf Coast, and they apparently believe that if a piece of
gear can't survive a 1 meter fall onto concrete, or being rained on and
rattling around in the back of a pickup truck for a few weeks, than
there's obviously something wrong with it anyway. It makes for a good
business in replacing switching, connectors and cracked LCDs.


Which distinctly falls under the category of REPAIR, NOT
calibration.