Re: [volt-nuts] AC Voltage Measurement Standards
Fellow Volt Nuts, The ultimate standard of AC Voltage is still primary sets of Thermal Converters that are characterised in terms of their thermal models and the modelled lumped elements ( inductive and capacitance effects). The programmable AC JJA's are very stable and reproducible AC sources cannot be primary references in themselves because their frequency response (although modelled) is still calibrated against other standards mostly TVC's. To those who have requested a copy of the paper on calibrating thermal converters against other converters please be patient and I will try and get my response over the weekend. Kind Regards, Stephen Grady Sydney Australia -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Tom Knox Sent: Friday, 11 July 2014 9:47 AM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] AC Voltage Measurement Standards The ultimate AC standard would be NIST's AC Josephson junction array. Sam Benz and his team continue to make advances, pushing the accuracy and output level. They have also substantially reduced the needed electronics placing much of the peripheral electronics in a custom built two-U enclosure. NIST has also recently introduced a fully programmable JJA that automates most of the set up and operation. It won't be long before we need 10 1/2 digit DMM's Cheers; Thomas Knox From: acb...@gmx.de To: volt-nuts@febo.com Date: Fri, 11 Jul 2014 01:13:44 +0200 Subject: Re: [volt-nuts] AC Voltage Measurement Standards in a nutshell, what i am doing is that I first establish the dc (+/-) output of the ref. TVC at nominal and then determine the ac voltage from a precision, highly linear (datron 4808) ac source that generates that default output voltage at the key frequencies. that establishes a set of ac voltage settings. for these the deviations of the TVC are known from the calibration. then I do the same with the TVC to be calibrated. (factor of 2 nom. voltage is important to stay within allowable range). that way you can link both. sure, sending all to cal is more precise, if you get the right lab at least, but also very expensive. would sure be interested in your tech paper Gesendet: Donnerstag, 10. Juli 2014 um 13:27 Uhr Von: Stephen Grady grady.st...@gmail.com An: 'Discussion of precise voltage measurement' volt-nuts@febo.com Betreff: Re: [volt-nuts] AC Voltage Measurement Standards Todd and anyone else would is interested, Measuring a Thermal Converter against another Thermal Converter is a bit of a black art. The main problem is thermal converters are a square law device that is if you change the input voltage by a factor of 2 the output voltage will change by a factor of approximately 4. Now I say approximately because for most thermal converters like the Fluke 540B, A55, Ballantine and Holts the actual factor can be anywhere from 1.4 to 1.8 due to losses in the thermal converter. In the literature you often see this factor refer to as the N factors. Each thermal converter will have its own N factor which must be measured to make sense of the measurements. It even becomes more difficult in that the AC-DC difference of a thermal converter is defined as (Vac-Vdc)/Vdc where Vac and Vdc are the inputs to a thermal converter which give an equal output from the converter. Also Vdc is the mean of the forward and reverse DC voltages. The problem is that when you have two converters connected in parallel you cannot balance both converters AC and DC inputs to produce equal voltage out of the converters at the same time because each converter has its own AC-DC difference and its own N factor. It anyone is interested I can send them a technical paper that describes this process and the appropriate math to use but I cannot send it to the list due to copyright issues. Kind Regards, Stephen Grady Sydney Australia -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Todd Micallef Sent: Thursday, 10 July 2014 2:36 AM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] AC Voltage Measurement Standards I would like to know more about your setup. Which source(s) are you using for the input and which nanovoltmeter(s) are you using to transfer the 10V TVC to your other converters? I remember you asking on PMEL forum about the accuracy of using a 34420A nanovoltmeter. I did not see a response as to whether you opted for an alternative like Keithley 2182(A) or a low noise preamplifier connected to a 3458A. I have done some reading about how NIST transfers their calibrations using two TVC's in parallel and I am guessing that is what you are doing. http://www.nist.gov/pml/div684/acdc/tcs.cfm To transfer the accuracy up/down to other TVC's at different rated voltages appears to be a difficult task
Re: [volt-nuts] AC Voltage Measurement Standards
Hello, For my 5cents worth, I also found Fluke 8506A's to be satisfactory - so long as they work. I only have one good remaining unit that does AC volts as well as DC. I like the HP 3458A for AC volts, but always need to apply corrections for serious AC volts work.A better solution I now use is the Datron 4920 units which are an order of magnitude more accurate than the 3458A across their full bandwidth. However, be aware of their input impedance and selection of cables - always use short coaxial. The 4920 impedance is around 100k to 400kohm (mostly frequency dependant) and this also varies during its sampling period. Otherwise they are great units, in the same ball park as a Fluke 5790 but way cheaper. For an AC source I thoroughly recommend the Datron 4200 or 4700 series, which are also way cheaper than the near equivalent Fluke 5700. Ben From: acb...@gmx.de Sent: Wednesday, July 09, 2014 9:29 PM To: Discussion of precise voltage measurement volt-nuts@febo.com Subject: Re: [volt-nuts] AC Voltage Measurement Standards J.L., it really depends on what level of accuracy you are looking for. The gold standard obviously is the Fluke 792A. That is probably not an option. The Fluke 8606 is more on the lower end side (dont get me wrong, compared to the 792A), it does not really bring much improvements compared to the 3458A operated in the AC SYNC mode, but maybe it is good enogh for what you want to do. In that range are also e.g. the RS ac voltmeters, but their focus is more in the higher frequency area. Very good accuracies are achieved by thermal converters (Ballantine...). You can do DC to AC comparison measurements with a few ppm accuracy. But measurements are slow, and you need a nanovolt meter. I personally did the following: I got a Ballantine 1605A transfer voltmeter. This is comparable to the 792A in a way, except it was much cheaper. It is automatic, much easier to use than the Fluke 540 and goes up to I think 100MHz. This can be used for percision calibrations as a working standard. The calibration of this meter as well as others (e.g. the 3458A in its AC mode) I am doing with a set of thermal converters (0.5V to 100V). One of which (10V) has been externally calibrated up to 30MHz, cal of the others are derived from it. That way I am deriving everything from a very precisely (few ppm) calibrated 10V TVC. Overall, this saves cost on the calibration side, allows for high accuracy and measurement speed is good. Gesendet: Mittwoch, 09. Juli 2014 um 06:20 Uhr Von: John Phillips An: mi...@vincentelectronics.com, Discussion of precise voltage measurement Betreff: Re: [volt-nuts] AC Voltage Measurement Standards J. L. , I do not know what level you are willing to pay for. I do not work in a real high end lab but we seem to get by with checking our secondary standards with a 3458A before and after we send it to gary to be calibrated. We use our 10 volts and 10K resistor to calibrate the 3458A before we send it in and then after. We look at the before and after data as well to come up with new values for the units. Comes down to using the 3458A as the primary standard filtered by our history. The different AC measurement methods in statistical mode can give you a good idea where your AC values really are. I would like to know how that compares with what the extra hardware can do. On Tue, Jul 8, 2014 at 7:52 PM, Mitch Van Ochten mi...@vincentelectronics.com wrote: Joe, I used a Fluke 540 for a while, and also the Fluke 8506A. The Fluke 540 is MUCH more difficult to use. You need to flip the switch between two positions rapidly and the results you get depend somewhat on how rapidly you make the transition. For AC volts the 8506A seems very nice. Best regards, mitch -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of J. L. Trantham Sent: Tuesday, July 08, 2014 9:46 PM To: Discussion of precise voltage measurement Subject: [volt-nuts] AC Voltage Measurement Standards I've been thinking about adding an AC Voltage Measurement Standard to my shop. It would appear that most of these have to do with thermal converters. Does anyone have any thoughts about this? I've been thinking about a Fluke 540B, 8506A, or a collection of A55 Thermal Converters. I have accurate DC measurement tools and DC standards. I would appreciate any thoughts. Thanks in advance. Joe ___ 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
Re: [volt-nuts] AC Voltage Measurement Standards
Todd and anyone else would is interested, Measuring a Thermal Converter against another Thermal Converter is a bit of a black art. The main problem is thermal converters are a square law device that is if you change the input voltage by a factor of 2 the output voltage will change by a factor of approximately 4. Now I say approximately because for most thermal converters like the Fluke 540B, A55, Ballantine and Holts the actual factor can be anywhere from 1.4 to 1.8 due to losses in the thermal converter. In the literature you often see this factor refer to as the N factors. Each thermal converter will have its own N factor which must be measured to make sense of the measurements. It even becomes more difficult in that the AC-DC difference of a thermal converter is defined as (Vac-Vdc)/Vdc where Vac and Vdc are the inputs to a thermal converter which give an equal output from the converter. Also Vdc is the mean of the forward and reverse DC voltages. The problem is that when you have two converters connected in parallel you cannot balance both converters AC and DC inputs to produce equal voltage out of the converters at the same time because each converter has its own AC-DC difference and its own N factor. It anyone is interested I can send them a technical paper that describes this process and the appropriate math to use but I cannot send it to the list due to copyright issues. Kind Regards, Stephen Grady Sydney Australia -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Todd Micallef Sent: Thursday, 10 July 2014 2:36 AM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] AC Voltage Measurement Standards I would like to know more about your setup. Which source(s) are you using for the input and which nanovoltmeter(s) are you using to transfer the 10V TVC to your other converters? I remember you asking on PMEL forum about the accuracy of using a 34420A nanovoltmeter. I did not see a response as to whether you opted for an alternative like Keithley 2182(A) or a low noise preamplifier connected to a 3458A. I have done some reading about how NIST transfers their calibrations using two TVC's in parallel and I am guessing that is what you are doing. http://www.nist.gov/pml/div684/acdc/tcs.cfm To transfer the accuracy up/down to other TVC's at different rated voltages appears to be a difficult task since they typically need at least half the rated max voltage to be within spec. It would be similar to starting with a SR104 standard and transferring its value through a set of SR1010 and SR1050 resistors using an ESI 242. I have a few AC sources, and I would like to be able to verify my TVC's without sending all of them out for cal. Ballantine quoted $600+ per TVC and I haven't checked what Fluke would charge for each A55. Todd I personally did the following: I got a Ballantine 1605A transfer voltmeter. This is comparable to the 792A in a way, except it was much cheaper. It is automatic, much easier to use than the Fluke 540 and goes up to I think 100MHz. This can be used for percision calibrations as a working standard. The calibration of this meter as well as others (e.g. the 3458A in its AC mode) I am doing with a set of thermal converters (0.5V to 100V). One of which (10V) has been externally calibrated up to 30MHz, cal of the others are derived from it. That way I am deriving everything from a very precisely (few ppm) calibrated 10V TVC. Overall, this saves cost on the calibration side, allows for high accuracy and measurement speed is good. ___ 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ 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.
Re: [volt-nuts] AC Voltage Measurement Standards
Ben, Do you have the 4921 Current Shunt Adapter option for the 4920? I have not found any information on it other than what is listed in the 4920 user's handbook. It mentions the unit simulates the impedance of a 540B. The guide says that the instructions are included with the 4921. Do you happen to have a copy of that document? The 4920 user's guide is on the KO4BB website. Thanks, Todd On Thu, Jul 10, 2014 at 5:17 AM, ben b...@veritechmeasurements.com.au wrote: Hello, For my 5cents worth, I also found Fluke 8506A's to be satisfactory - so long as they work. I only have one good remaining unit that does AC volts as well as DC. I like the HP 3458A for AC volts, but always need to apply corrections for serious AC volts work.A better solution I now use is the Datron 4920 units which are an order of magnitude more accurate than the 3458A across their full bandwidth. However, be aware of their input impedance and selection of cables - always use short coaxial. The 4920 impedance is around 100k to 400kohm (mostly frequency dependant) and this also varies during its sampling period. Otherwise they are great units, in the same ball park as a Fluke 5790 but way cheaper. For an AC source I thoroughly recommend the Datron 4200 or 4700 series, which are also way cheaper than the near equivalent Fluke 5700. Ben ___ 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.
Re: [volt-nuts] AC Voltage Measurement Standards
I have a set of 7 TVCs, from 1 to 100V. having them all calibrated externally is just too expensive. There is no doubt that having all 7 TVCs calibrated at NIST or PTB, wherever you are, is much more precise, I will just not spend it and live with the accuracy I get. As source I am using a Datron 4808, as nanovolt meter an Agilent 34420. Problem with this is, you pointed it out, Agilent does not specify transfer accuracy, I am in contact with them, so far no outcome though, not sure there will be any. So I have not yet completed my error calculation for the TVC cal. I will probably end up doing some calculations based on data sheet an then vaildate by measurement. Need that on the 10mv range only, so effort is limited. additionally I also have a ratio transformer, which is good to about 10kHz, that also allows for validating the TVC results by comparison in lower frequency ranges and narrow down the tolerances. I do have a 182-M, but do not trust it, I saw a lot of drift doing some other measurements although it passes performance verification, and I just got a 2182, which has an issue that needs to be fixed first. I need to say the 34420a is very stable with the digital filter switched on and you can see the nanovolts walk until the TVC stabilizes. vice versa, if you have an issue in the setup (thermal drifts...), you also seethat very well, so the filter is not hiding this. as far as your comment re. calibrating a set of resistor cal from one calibrated one, whats wrong with it? if you do that with a stable voltage and by voltage divider measurement using the linearity of the 3458A, you end up with pretty decent accuracies. I cannot comment on the 242, just did some quick checks some time ago and my quick assessment then was it is worse/not better than the 3458a method. Gesendet: Mittwoch, 09. Juli 2014 um 16:35 Uhr Von: Todd Micallef tmical...@gmail.com An: Discussion of precise voltage measurement volt-nuts@febo.com Betreff: Re: [volt-nuts] AC Voltage Measurement Standards I would like to know more about your setup. Which source(s) are you using for the input and which nanovoltmeter(s) are you using to transfer the 10V TVC to your other converters? I remember you asking on PMEL forum about the accuracy of using a 34420A nanovoltmeter. I did not see a response as to whether you opted for an alternative like Keithley 2182(A) or a low noise preamplifier connected to a 3458A. I have done some reading about how NIST transfers their calibrations using two TVC's in parallel and I am guessing that is what you are doing. http://www.nist.gov/pml/div684/acdc/tcs.cfm To transfer the accuracy up/down to other TVC's at different rated voltages appears to be a difficult task since they typically need at least half the rated max voltage to be within spec. It would be similar to starting with a SR104 standard and transferring its value through a set of SR1010 and SR1050 resistors using an ESI 242. I have a few AC sources, and I would like to be able to verify my TVC's without sending all of them out for cal. Ballantine quoted $600+ per TVC and I haven't checked what Fluke would charge for each A55. Todd I personally did the following: I got a Ballantine 1605A transfer voltmeter. This is comparable to the 792A in a way, except it was much cheaper. It is automatic, much easier to use than the Fluke 540 and goes up to I think 100MHz. This can be used for percision calibrations as a working standard. The calibration of this meter as well as others (e.g. the 3458A in its AC mode) I am doing with a set of thermal converters (0.5V to 100V). One of which (10V) has been externally calibrated up to 30MHz, cal of the others are derived from it. That way I am deriving everything from a very precisely (few ppm) calibrated 10V TVC. Overall, this saves cost on the calibration side, allows for high accuracy and measurement speed is good. ___ 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.
Re: [volt-nuts] AC Voltage Measurement Standards
in a nutshell, what i am doing is that I first establish the dc (+/-) output of the ref. TVC at nominal and then determine the ac voltage from a precision, highly linear (datron 4808) ac source that generates that default output voltage at the key frequencies. that establishes a set of ac voltage settings. for these the deviations of the TVC are known from the calibration. then I do the same with the TVC to be calibrated. (factor of 2 nom. voltage is important to stay within allowable range). that way you can link both. sure, sending all to cal is more precise, if you get the right lab at least, but also very expensive. would sure be interested in your tech paper Gesendet: Donnerstag, 10. Juli 2014 um 13:27 Uhr Von: Stephen Grady grady.st...@gmail.com An: 'Discussion of precise voltage measurement' volt-nuts@febo.com Betreff: Re: [volt-nuts] AC Voltage Measurement Standards Todd and anyone else would is interested, Measuring a Thermal Converter against another Thermal Converter is a bit of a black art. The main problem is thermal converters are a square law device that is if you change the input voltage by a factor of 2 the output voltage will change by a factor of approximately 4. Now I say approximately because for most thermal converters like the Fluke 540B, A55, Ballantine and Holts the actual factor can be anywhere from 1.4 to 1.8 due to losses in the thermal converter. In the literature you often see this factor refer to as the N factors. Each thermal converter will have its own N factor which must be measured to make sense of the measurements. It even becomes more difficult in that the AC-DC difference of a thermal converter is defined as (Vac-Vdc)/Vdc where Vac and Vdc are the inputs to a thermal converter which give an equal output from the converter. Also Vdc is the mean of the forward and reverse DC voltages. The problem is that when you have two converters connected in parallel you cannot balance both converters AC and DC inputs to produce equal voltage out of the converters at the same time because each converter has its own AC-DC difference and its own N factor. It anyone is interested I can send them a technical paper that describes this process and the appropriate math to use but I cannot send it to the list due to copyright issues. Kind Regards, Stephen Grady Sydney Australia -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Todd Micallef Sent: Thursday, 10 July 2014 2:36 AM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] AC Voltage Measurement Standards I would like to know more about your setup. Which source(s) are you using for the input and which nanovoltmeter(s) are you using to transfer the 10V TVC to your other converters? I remember you asking on PMEL forum about the accuracy of using a 34420A nanovoltmeter. I did not see a response as to whether you opted for an alternative like Keithley 2182(A) or a low noise preamplifier connected to a 3458A. I have done some reading about how NIST transfers their calibrations using two TVC's in parallel and I am guessing that is what you are doing. http://www.nist.gov/pml/div684/acdc/tcs.cfm To transfer the accuracy up/down to other TVC's at different rated voltages appears to be a difficult task since they typically need at least half the rated max voltage to be within spec. It would be similar to starting with a SR104 standard and transferring its value through a set of SR1010 and SR1050 resistors using an ESI 242. I have a few AC sources, and I would like to be able to verify my TVC's without sending all of them out for cal. Ballantine quoted $600+ per TVC and I haven't checked what Fluke would charge for each A55. Todd I personally did the following: I got a Ballantine 1605A transfer voltmeter. This is comparable to the 792A in a way, except it was much cheaper. It is automatic, much easier to use than the Fluke 540 and goes up to I think 100MHz. This can be used for percision calibrations as a working standard. The calibration of this meter as well as others (e.g. the 3458A in its AC mode) I am doing with a set of thermal converters (0.5V to 100V). One of which (10V) has been externally calibrated up to 30MHz, cal of the others are derived from it. That way I am deriving everything from a very precisely (few ppm) calibrated 10V TVC. Overall, this saves cost on the calibration side, allows for high accuracy and measurement speed is good. ___ 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ volt-nuts
Re: [volt-nuts] AC Voltage Measurement Standards
The ultimate AC standard would be NIST's AC Josephson junction array. Sam Benz and his team continue to make advances, pushing the accuracy and output level. They have also substantially reduced the needed electronics placing much of the peripheral electronics in a custom built two-U enclosure. NIST has also recently introduced a fully programmable JJA that automates most of the set up and operation. It won't be long before we need 10 1/2 digit DMM's Cheers; Thomas Knox From: acb...@gmx.de To: volt-nuts@febo.com Date: Fri, 11 Jul 2014 01:13:44 +0200 Subject: Re: [volt-nuts] AC Voltage Measurement Standards in a nutshell, what i am doing is that I first establish the dc (+/-) output of the ref. TVC at nominal and then determine the ac voltage from a precision, highly linear (datron 4808) ac source that generates that default output voltage at the key frequencies. that establishes a set of ac voltage settings. for these the deviations of the TVC are known from the calibration. then I do the same with the TVC to be calibrated. (factor of 2 nom. voltage is important to stay within allowable range). that way you can link both. sure, sending all to cal is more precise, if you get the right lab at least, but also very expensive. would sure be interested in your tech paper Gesendet: Donnerstag, 10. Juli 2014 um 13:27 Uhr Von: Stephen Grady grady.st...@gmail.com An: 'Discussion of precise voltage measurement' volt-nuts@febo.com Betreff: Re: [volt-nuts] AC Voltage Measurement Standards Todd and anyone else would is interested, Measuring a Thermal Converter against another Thermal Converter is a bit of a black art. The main problem is thermal converters are a square law device that is if you change the input voltage by a factor of 2 the output voltage will change by a factor of approximately 4. Now I say approximately because for most thermal converters like the Fluke 540B, A55, Ballantine and Holts the actual factor can be anywhere from 1.4 to 1.8 due to losses in the thermal converter. In the literature you often see this factor refer to as the N factors. Each thermal converter will have its own N factor which must be measured to make sense of the measurements. It even becomes more difficult in that the AC-DC difference of a thermal converter is defined as (Vac-Vdc)/Vdc where Vac and Vdc are the inputs to a thermal converter which give an equal output from the converter. Also Vdc is the mean of the forward and reverse DC voltages. The problem is that when you have two converters connected in parallel you cannot balance both converters AC and DC inputs to produce equal voltage out of the converters at the same time because each converter has its own AC-DC difference and its own N factor. It anyone is interested I can send them a technical paper that describes this process and the appropriate math to use but I cannot send it to the list due to copyright issues. Kind Regards, Stephen Grady Sydney Australia -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Todd Micallef Sent: Thursday, 10 July 2014 2:36 AM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] AC Voltage Measurement Standards I would like to know more about your setup. Which source(s) are you using for the input and which nanovoltmeter(s) are you using to transfer the 10V TVC to your other converters? I remember you asking on PMEL forum about the accuracy of using a 34420A nanovoltmeter. I did not see a response as to whether you opted for an alternative like Keithley 2182(A) or a low noise preamplifier connected to a 3458A. I have done some reading about how NIST transfers their calibrations using two TVC's in parallel and I am guessing that is what you are doing. http://www.nist.gov/pml/div684/acdc/tcs.cfm To transfer the accuracy up/down to other TVC's at different rated voltages appears to be a difficult task since they typically need at least half the rated max voltage to be within spec. It would be similar to starting with a SR104 standard and transferring its value through a set of SR1010 and SR1050 resistors using an ESI 242. I have a few AC sources, and I would like to be able to verify my TVC's without sending all of them out for cal. Ballantine quoted $600+ per TVC and I haven't checked what Fluke would charge for each A55. Todd I personally did the following: I got a Ballantine 1605A transfer voltmeter. This is comparable to the 792A in a way, except it was much cheaper. It is automatic, much easier to use than the Fluke 540 and goes up to I think 100MHz. This can be used for percision calibrations as a working standard. The calibration of this meter as well as others (e.g. the 3458A in its AC mode) I am doing with a set of thermal converters (0.5V
Re: [volt-nuts] AC Voltage Measurement Standards
The remark about calibrating the resistors was merely an example of how I thought you may have been transferring the calibration of the 10V TVC. My first thought was that you compared the 10V TVC to the next closest model at fixed points. The inter-comparison would then continue from that model to the next value down (or up). I had a hard time trying to understand how that could be accurate, and the thought of using a ratio transformer didn't cross my mind. Thanks for the explanation. I can see how the costs of calibrating a TVC can be so high. I am guessing few labs possess the equipment to calibrate them and places like Ballantine probably use NIST for their cals. Todd as far as your comment re. calibrating a set of resistor cal from one calibrated one, whats wrong with it? if you do that with a stable voltage and by voltage divider measurement using the linearity of the 3458A, you end up with pretty decent accuracies. I cannot comment on the 242, just did some quick checks some time ago and my quick assessment then was it is worse/not better than the 3458a method. ___ 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.
Re: [volt-nuts] AC Voltage Measurement Standards
In message trinity-2e0df2e8-1978-44c0-8d7f-1248885e1b2e-1404906840284@3capp-gmx-bs72, acbern@gm x.de writes: Very good accuracies are achieved by thermal converters (Ballantine...). You can do DC to AC comparison measurements with a few ppm accuracy. But measurements are slow, and you need a nanovolt meter. And very stable surrounding temperature. Thermal converters measure the heating caused by the electric energy as a temperature increase over ambient temperature. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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.
Re: [volt-nuts] AC Voltage Measurement Standards
I also have a Ballentine 1605A. These are quite accurate, reasonably fast, wide frequency response instruments. They're microprocessor controlled and will do automatic measurements so you don't have to do manual nulling. It can also be calibrated against a DC standard, but that doesn't correct for frequency non linearity, of course. The manual is still available from Ballentine (for a silly amount of money). I don't see many of these on FleaBay, though. -- Bill Ezell -- The day Microsoft makes something that doesn't suck will be the day they make vacuum cleaners. ___ 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.
Re: [volt-nuts] AC Voltage Measurement Standards
I like the 5200A for a good stable unit up to 110 volts but if you go above that you would be better off with a 5100B which will do 1100 volts. On Tue, Jul 8, 2014 at 6:46 PM, J. L. Trantham jlt...@att.net wrote: I've been thinking about adding an AC Voltage Measurement Standard to my shop. It would appear that most of these have to do with thermal converters. Does anyone have any thoughts about this? I've been thinking about a Fluke 540B, 8506A, or a collection of A55 Thermal Converters. I have accurate DC measurement tools and DC standards. I would appreciate any thoughts. Thanks in advance. Joe ___ 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 ___ 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.
Re: [volt-nuts] AC Voltage Measurement Standards
John, Thanks for the reply. I have both of those. What I'm thinking about is a measurement standard. That is, how do I know that my 'standards' are accurate? That brings to mind the 'thermal converter' issue. The 8506A apparently uses a 'thermal converter' as part of its measurement process. The individual A55 Thermal Converters can be used for their various ranges but might be more expensive if you collect all of them. So, the question is how would you go about 'proving' that your reference is indeed accurate? As best I can tell, this has to do with comparing it to some DC reference by virtue of an RMS (thermal, as best I can tell) comparison. Joe -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of John Phillips Sent: Tuesday, July 08, 2014 8:57 PM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] AC Voltage Measurement Standards I like the 5200A for a good stable unit up to 110 volts but if you go above that you would be better off with a 5100B which will do 1100 volts. On Tue, Jul 8, 2014 at 6:46 PM, J. L. Trantham jlt...@att.net wrote: I've been thinking about adding an AC Voltage Measurement Standard to my shop. It would appear that most of these have to do with thermal converters. Does anyone have any thoughts about this? I've been thinking about a Fluke 540B, 8506A, or a collection of A55 Thermal Converters. I have accurate DC measurement tools and DC standards. I would appreciate any thoughts. Thanks in advance. Joe ___ 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 ___ 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.
Re: [volt-nuts] AC Voltage Measurement Standards
Joe, I used a Fluke 540 for a while, and also the Fluke 8506A. The Fluke 540 is MUCH more difficult to use. You need to flip the switch between two positions rapidly and the results you get depend somewhat on how rapidly you make the transition. For AC volts the 8506A seems very nice. Best regards, mitch -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of J. L. Trantham Sent: Tuesday, July 08, 2014 9:46 PM To: Discussion of precise voltage measurement Subject: [volt-nuts] AC Voltage Measurement Standards I've been thinking about adding an AC Voltage Measurement Standard to my shop. It would appear that most of these have to do with thermal converters. Does anyone have any thoughts about this? I've been thinking about a Fluke 540B, 8506A, or a collection of A55 Thermal Converters. I have accurate DC measurement tools and DC standards. I would appreciate any thoughts. Thanks in advance. Joe ___ 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.
Re: [volt-nuts] AC Voltage Measurement Standards
J. L. , I do not know what level you are willing to pay for. I do not work in a real high end lab but we seem to get by with checking our secondary standards with a 3458A before and after we send it to gary to be calibrated. We use our 10 volts and 10K resistor to calibrate the 3458A before we send it in and then after. We look at the before and after data as well to come up with new values for the units. Comes down to using the 3458A as the primary standard filtered by our history. The different AC measurement methods in statistical mode can give you a good idea where your AC values really are. I would like to know how that compares with what the extra hardware can do. On Tue, Jul 8, 2014 at 7:52 PM, Mitch Van Ochten mi...@vincentelectronics.com wrote: Joe, I used a Fluke 540 for a while, and also the Fluke 8506A. The Fluke 540 is MUCH more difficult to use. You need to flip the switch between two positions rapidly and the results you get depend somewhat on how rapidly you make the transition. For AC volts the 8506A seems very nice. Best regards, mitch -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of J. L. Trantham Sent: Tuesday, July 08, 2014 9:46 PM To: Discussion of precise voltage measurement Subject: [volt-nuts] AC Voltage Measurement Standards I've been thinking about adding an AC Voltage Measurement Standard to my shop. It would appear that most of these have to do with thermal converters. Does anyone have any thoughts about this? I've been thinking about a Fluke 540B, 8506A, or a collection of A55 Thermal Converters. I have accurate DC measurement tools and DC standards. I would appreciate any thoughts. Thanks in advance. Joe ___ 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. -- John Phillips ___ 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.
