Re: [volt-nuts] DMM calibration
I don't know what logo cal is, but between Z540 and 17025 is a
question of procedures and how they are done.
In metrology the procedures, and how strict they are, reduce the risk
of uncertainty in the final measurement. For example, some
procedures in Z540 can be 'interpreted' where in 17025 is explicit,
thus there is more room in Z540 for one lab to be worse than another,
or vice versa, which defeats the purpose of standardization. This
'intepretation' is fairly reduced when the device is cal'd by an
autocalibrator such for close case calibration DMMs, but becomes a
big issue with any manual cal.
If these do not mean anything to you and you do not need the data for
long term drift calculations, ISO 9001 is good to go.
IMHO the difference between all 3 is insignificant for 5.5 digit
DMMs, except for one's need for data.
At 12:30 PM 8/7/2013, Joseph Gray wrote:
I just got the following quote for getting my HP 3478A calibrated.
35.00 for ISO 9001 no data
87.50 for Z540 with data and uncertainties
275.00 for 17025 with data, uncertainties and logo calibration.
I still didn't get any explaination as to exactly what the lab does for
each of these price points. When I asked about the "Level 4" listed next to
the meter, I was told that it is the difficulty level. Still not telling me
much. I have read the procedure in the HP service manual and it is very
easy. You set some volt, amp, ohm values on the standard, then push some
buttons on the meter.
I understand about getting data or not, it is the other aspects that I
don't understand. What is Z540, 17025 and "logo calibration"?
Joe Gray
W5JG
Sincerely,
Marv
Philadelphia, PA
Specs for a 3478A
Brand HP Model 3478A Counts 303.099 TrueRMS X Display LCD Year 1983 Range Stability [ppm] Low High Resolution 1y
DC Volt 30m 300 100n 60 AC Volt 300m 300 1u 2000 Max Frequency 300k Resistance 30 30M 100u 160 DC Current 300m 3 1u 1500 AC Current 300m 3 1u 7200 Interface GPIB Battery backup X
If you do the adjustments with some hobby equipment wich an accuracy of say 20 to 30 ppm. Thats all within limits of this multimeter. You never see the difference.
In my opion, expensive adjustments and calibration for not so accurate equipment is a waste of money. Especialy when the calibration price exceeds the equipment price.
Regards
ElectronicsAndBooks@Yahoo.com
http://ElectronicsAndBooks.com
From: "Marv @ Home" marvin.gozum@comcast.net
To: Discussion of precise voltage measurement volt-nuts@febo.com; Discussion of precise voltage measurement volt-nuts@febo.com
Sent: Wednesday, August 7, 2013 6:53 PM
Subject: Re: [volt-nuts] DMM calibration
I don't know what logo cal is, but between Z540 and 17025 is a
question of procedures and how they are done.
In metrology the procedures, and how strict they are, reduce the risk
of uncertainty in the final measurement. For example, some
procedures in Z540 can be 'interpreted' where in 17025 is explicit,
thus there is more room in Z540 for one lab to be worse than another,
or vice versa, which defeats the purpose of standardization. This
'intepretation' is fairly reduced when the device is cal'd by an
autocalibrator such for close case calibration DMMs, but becomes a
big issue with any manual cal.
If these do not mean anything to you and you do not need the data for
long term drift calculations, ISO 9001 is good to go.
IMHO the difference between all 3 is insignificant for 5.5 digit
DMMs, except for one's need for data.
At 12:30 PM 8/7/2013, Joseph Gray wrote:
I just got the following quote for getting my HP 3478A calibrated.
35.00 for ISO 9001 no data
87.50 for Z540 with data and uncertainties
275.00 for 17025 with data, uncertainties and logo calibration.
I still didn't get any explaination as to exactly what the lab does for
each of these price points. When I asked about the "Level 4" listed next to
the meter, I was told that it is the difficulty level. Still not telling me
much. I have read the procedure in the HP service manual and it is very
easy. You set some volt, amp, ohm values on the standard, then push some
buttons on the meter.
I understand about getting data or not, it is the other aspects that I
don't understand. What is Z540, 17025 and "logo calibration"?
Joe Gray
W5JG
Sincerely,
Marv
Philadelphia, PA
volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.
-----Original Message-----
From: Electronics and Books
Sent: Thursday, August 08, 2013 12:54 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] DMM calibration
Specs for a 3478A
Brand HP Model 3478A Counts 303.099 TrueRMS X Display LCD Year 1983 Range
Stability [ppm] Low High Resolution 1y
DC Volt 30m 300 100n 60 AC Volt 300m 300 1u 2000 Max Frequency 300k
Resistance 30 30M 100u 160 DC Current 300m 3 1u 1500 AC Current 300m 3
1u 7200 Interface GPIB Battery backup X
If you do the adjustments with some hobby equipment wich an accuracy of say
20 to 30 ppm. Thats all within limits of this multimeter. You never see the
difference.
In my opion, expensive adjustments and calibration for not so accurate
equipment is a waste of money. Especialy when the calibration price exceeds
the equipment price.
Regards
ElectronicsAndBooks@Yahoo.com
http://ElectronicsAndBooks.com
I would like to say - "you are absolutely correct" - I have recently been
quoted for a 3458A which requires a new set of ROM's and re-cal. - the cost
was greater than I paid for the S/H instrument just 4 years ago. These
prices are OK for large Companies who can recover the VAT for a start !
......... but cannot be justified for hobbyists. Most of us have items of
equipment that have been calibrated in recent times, and other precision
items like resistors and higher spec. zeners that when you make comparisons
can verify your DVM's . I recently purchased a Keithley 2015 for less than
some cal. charges, this was calibrated in 2008 and I would say that it is
still in very good calibration now.
Roy P
From: "Marv @ Home" marvin.gozum@comcast.net
To: Discussion of precise voltage measurement volt-nuts@febo.com;
Discussion of precise voltage measurement volt-nuts@febo.com
Sent: Wednesday, August 7, 2013 6:53 PM
Subject: Re: [volt-nuts] DMM calibration
I don't know what logo cal is, but between Z540 and 17025 is a
question of procedures and how they are done.
In metrology the procedures, and how strict they are, reduce the risk
of uncertainty in the final measurement. For example, some
procedures in Z540 can be 'interpreted' where in 17025 is explicit,
thus there is more room in Z540 for one lab to be worse than another,
or vice versa, which defeats the purpose of standardization. This
'intepretation' is fairly reduced when the device is cal'd by an
autocalibrator such for close case calibration DMMs, but becomes a
big issue with any manual cal.
If these do not mean anything to you and you do not need the data for
long term drift calculations, ISO 9001 is good to go.
IMHO the difference between all 3 is insignificant for 5.5 digit
DMMs, except for one's need for data.
At 12:30 PM 8/7/2013, Joseph Gray wrote:
I just got the following quote for getting my HP 3478A calibrated.
35.00 for ISO 9001 no data
87.50 for Z540 with data and uncertainties
275.00 for 17025 with data, uncertainties and logo calibration.
I still didn't get any explaination as to exactly what the lab does for
each of these price points. When I asked about the "Level 4" listed next to
the meter, I was told that it is the difficulty level. Still not telling me
much. I have read the procedure in the HP service manual and it is very
easy. You set some volt, amp, ohm values on the standard, then push some
buttons on the meter.
I understand about getting data or not, it is the other aspects that I
don't understand. What is Z540, 17025 and "logo calibration"?
Joe Gray
W5JG
Sincerely,
Marv
Philadelphia, PA
volt-nuts mailing list -- volt-nuts@febo.com
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I had my eBay special $90 HP3478A calibrated by our internal cal lab (traceable to NIST). Based on the sticker, the last cal was 5 years old. The instrument was well within all specs by a wide margin (most readings were within 20% of the stated tolerance, which after 5 years is pretty good.
Didier KO4BB
Roy Phillips phill.r1@btinternet.com wrote:
-----Original Message-----
From: Electronics and Books
Sent: Thursday, August 08, 2013 12:54 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] DMM calibration
Specs for a 3478A
Brand HP Model 3478A Counts 303.099 TrueRMS X Display LCD Year 1983
Range
Stability [ppm] Low High Resolution 1y
DC Volt 30m 300 100n 60 AC Volt 300m 300 1u 2000 Max Frequency 300k
Resistance 30 30M 100u 160 DC Current 300m 3 1u 1500 AC Current
300m 3
1u 7200 Interface GPIB Battery backup X
If you do the adjustments with some hobby equipment wich an accuracy of
say
20 to 30 ppm. Thats all within limits of this multimeter. You never see
the
difference.
In my opion, expensive adjustments and calibration for not so accurate
equipment is a waste of money. Especialy when the calibration price
exceeds
the equipment price.
Regards
ElectronicsAndBooks@Yahoo.com
http://ElectronicsAndBooks.com
I would like to say - "you are absolutely correct" - I have recently
been
quoted for a 3458A which requires a new set of ROM's and re-cal. - the
cost
was greater than I paid for the S/H instrument just 4 years ago. These
prices are OK for large Companies who can recover the VAT for a start !
......... but cannot be justified for hobbyists. Most of us have items
of
equipment that have been calibrated in recent times, and other
precision
items like resistors and higher spec. zeners that when you make
comparisons
can verify your DVM's . I recently purchased a Keithley 2015 for less
than
some cal. charges, this was calibrated in 2008 and I would say that it
is
still in very good calibration now.
Roy P
From: "Marv @ Home" marvin.gozum@comcast.net
To: Discussion of precise voltage measurement volt-nuts@febo.com;
Discussion of precise voltage measurement volt-nuts@febo.com
Sent: Wednesday, August 7, 2013 6:53 PM
Subject: Re: [volt-nuts] DMM calibration
I don't know what logo cal is, but between Z540 and 17025 is a
question of procedures and how they are done.
In metrology the procedures, and how strict they are, reduce the risk
of uncertainty in the final measurement. For example, some
procedures in Z540 can be 'interpreted' where in 17025 is explicit,
thus there is more room in Z540 for one lab to be worse than another,
or vice versa, which defeats the purpose of standardization. This
'intepretation' is fairly reduced when the device is cal'd by an
autocalibrator such for close case calibration DMMs, but becomes a
big issue with any manual cal.
If these do not mean anything to you and you do not need the data for
long term drift calculations, ISO 9001 is good to go.
IMHO the difference between all 3 is insignificant for 5.5 digit
DMMs, except for one's need for data.
At 12:30 PM 8/7/2013, Joseph Gray wrote:
I just got the following quote for getting my HP 3478A calibrated.
35.00 for ISO 9001 no data
87.50 for Z540 with data and uncertainties
275.00 for 17025 with data, uncertainties and logo calibration.
I still didn't get any explaination as to exactly what the lab does
for
each of these price points. When I asked about the "Level 4" listed
next to
the meter, I was told that it is the difficulty level. Still not
telling me
much. I have read the procedure in the HP service manual and it is
very
easy. You set some volt, amp, ohm values on the standard, then push
some
buttons on the meter.
I understand about getting data or not, it is the other aspects that I
don't understand. What is Z540, 17025 and "logo calibration"?
Joe Gray
W5JG
Sincerely,
Marv
Philadelphia, PA
volt-nuts mailing list -- volt-nuts@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@febo.com
To unsubscribe, go to
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and follow the instructions there.
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To unsubscribe, go to
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--
Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other things.
You will find that most old "stuff" does not drift as much as the new
"stuff".
Most resistors seem to drift in a damped sine wave rate with a period of
about 4 years.
On Thu, Aug 8, 2013 at 10:10 AM, Didier Juges shalimr9@gmail.com wrote:
I had my eBay special $90 HP3478A calibrated by our internal cal lab
(traceable to NIST). Based on the sticker, the last cal was 5 years old.
The instrument was well within all specs by a wide margin (most readings
were within 20% of the stated tolerance, which after 5 years is pretty good.
Didier KO4BB
Roy Phillips phill.r1@btinternet.com wrote:
-----Original Message-----
From: Electronics and Books
Sent: Thursday, August 08, 2013 12:54 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] DMM calibration
Specs for a 3478A
Brand HP Model 3478A Counts 303.099 TrueRMS X Display LCD Year 1983
Range
Stability [ppm] Low High Resolution 1y
DC Volt 30m 300 100n 60 AC Volt 300m 300 1u 2000 Max Frequency 300k
Resistance 30 30M 100u 160 DC Current 300m 3 1u 1500 AC Current
300m 3
1u 7200 Interface GPIB Battery backup X
If you do the adjustments with some hobby equipment wich an accuracy of
say
20 to 30 ppm. Thats all within limits of this multimeter. You never see
the
difference.
In my opion, expensive adjustments and calibration for not so accurate
equipment is a waste of money. Especialy when the calibration price
exceeds
the equipment price.
Regards
ElectronicsAndBooks@Yahoo.com
http://ElectronicsAndBooks.com
I would like to say - "you are absolutely correct" - I have recently
been
quoted for a 3458A which requires a new set of ROM's and re-cal. - the
cost
was greater than I paid for the S/H instrument just 4 years ago. These
prices are OK for large Companies who can recover the VAT for a start !
......... but cannot be justified for hobbyists. Most of us have items
of
equipment that have been calibrated in recent times, and other
precision
items like resistors and higher spec. zeners that when you make
comparisons
can verify your DVM's . I recently purchased a Keithley 2015 for less
than
some cal. charges, this was calibrated in 2008 and I would say that it
is
still in very good calibration now.
Roy P
From: "Marv @ Home" marvin.gozum@comcast.net
To: Discussion of precise voltage measurement volt-nuts@febo.com;
Discussion of precise voltage measurement volt-nuts@febo.com
Sent: Wednesday, August 7, 2013 6:53 PM
Subject: Re: [volt-nuts] DMM calibration
I don't know what logo cal is, but between Z540 and 17025 is a
question of procedures and how they are done.
In metrology the procedures, and how strict they are, reduce the risk
of uncertainty in the final measurement. For example, some
procedures in Z540 can be 'interpreted' where in 17025 is explicit,
thus there is more room in Z540 for one lab to be worse than another,
or vice versa, which defeats the purpose of standardization. This
'intepretation' is fairly reduced when the device is cal'd by an
autocalibrator such for close case calibration DMMs, but becomes a
big issue with any manual cal.
If these do not mean anything to you and you do not need the data for
long term drift calculations, ISO 9001 is good to go.
IMHO the difference between all 3 is insignificant for 5.5 digit
DMMs, except for one's need for data.
At 12:30 PM 8/7/2013, Joseph Gray wrote:
I just got the following quote for getting my HP 3478A calibrated.
35.00 for ISO 9001 no data
87.50 for Z540 with data and uncertainties
275.00 for 17025 with data, uncertainties and logo calibration.
I still didn't get any explaination as to exactly what the lab does
for
each of these price points. When I asked about the "Level 4" listed
next to
the meter, I was told that it is the difficulty level. Still not
telling me
much. I have read the procedure in the HP service manual and it is
very
easy. You set some volt, amp, ohm values on the standard, then push
some
buttons on the meter.
I understand about getting data or not, it is the other aspects that I
don't understand. What is Z540, 17025 and "logo calibration"?
Joe Gray
W5JG
Sincerely,
Marv
Philadelphia, PA
volt-nuts mailing list -- volt-nuts@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@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@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.
--
Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other
things.
volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.
--
John Phillips
On 8 August 2013 18:58, John Phillips john.phillips0@gmail.com wrote:
You will find that most old "stuff" does not drift as much as the new
"stuff".
Most resistors seem to drift in a damped sine wave rate with a period of
about 4 years.
Is there any theory behind that? It's the first time I have heard of
the 4 year damped sine wave!
Dave
I did some work for a resistor manufacture and was told about resistor
drift. It does not keep going the same direction forever it does hit a
limit and start back the other way. 4 years is just an approximation. The
material and environment will have a lot to do with the period. Agilent
burns in their voltage references and the main difference is how long
they "cook" them. They also screen to get a better reference. evenhandedly
the drift rate and amplitude drops. In a few hundred years things will be
stable or broken. Broken is very stable. Like wire resistance will not keep
going down till it hits 0 or up until it opens.
Agilent says do not turn your 3458A off or it will not be as stable as if
it has been running for years.
Agilent move some reference manufacturing off shore, when the references
met the stability numbers they were harvested and put in stock bins. Latter
when they were used they no longer met the spec. There was a memo sent out
that if you had one of these references its stability should be withing
spec if the meter was not turned off for 6 mo. (that is how I remember it).