There are a host of things that will cause a JJA to be off voltage... not the least of which is temperature and frequency. Absent other standards to compare with your JJA, you are really operating in the blind. The only major advantage to the JJA, and the reason it is given primary standard status, is it relates voltage, to frequency. If the pumping frequency is offset for some reason, the voltage will be wrong by a similar amount. Do you imagine that NIST uses only one JJA to hold the nation's standard volt? -Chuck Harris Tom Knox wrote: > The physics of a properly run JJA will always produce the same result so you do > not need additional units for comparison. That is the point of a world wide > quantum voltage standard defined as K > J-90 = 483 597.9 GHz/V . Just has the > Hyperfine Transition of Cesium at about 9.192631770GHz is used to define the > second. What is neat about the work NIST has done recently is that it has > automated the System for ease of use and reduced the price to the point that it > should see much wider use in day to day metrology. Having your Agilent 3458A > calibrated on a JJA may not yield much difference over a Fluke 5730A cal, but once > the meter has been run a few years characterizing the A to D converter and 10VAC > range would only need to be done once and could substantially improve performance. > I personally think that the face of calibration will change in coming years, > rather then simple time based cal periods, instruments will contain complex > environmental sensor packages that will constantly monitor the instruments > environment . S o calibration will be based more on the instruments exposure to > extreme conditions then simple time. I bet the act of shipping has more effect on > cal then years sitting in a lab. So if for example a 3458A was put in an > environmental chamber on a shaker table I am sure we find that up to a certain > point enviromental conditions would have little effect on cal but at some point > would have a major effect. Once documented the cals would be based more on > environmental exposure. In addition I am sure some environmental effects on cal > are repeatable and could be documented so if monitored they could be compensated > for extending time between cals. So in the future you would see your instrument > display "environment conditions exceeded" "cal require", with perhaps even a > display of currently instrument uncertainty. This could change the face of > calibration and become a multi-billion dollar industry. > > Thomas Knox > > > >> Date: Sun, 16 Feb 2014 07:06:18 -0700 From: nova@npgcable.com To: >> volt-nuts@febo.com Subject: Re: [volt-nuts] JJA progress report >> >> >> If Earth is subjected to a GRB strong enough to damage ground based >> electronics, we are all going to have much more urgent problems than wondering >> if a JVS is operating properly. Same for an EMP. Lightning, however, might >> pose a more localized and serious threat. >> >> Part of your training as an expert operator will include techniques to dissuade >> various critters from considering the JVS for their burial ceremonies. >> >> Carrying your best zener reference to the nearest facility with another JVS >> would be less expensive than buying and operating a second or third system. >> >> Joe >> >> >> On 2/16/2014 12:58 AM, cheater00 . wrote: >>> How do you know the primary standard is not off? That is, how do you know it's >>> still "primary"? Maybe a gamma ray burst from a supernova damaged some of the >>> machinery inside, or a colony of crazy ants crawled in and died inside. >>> >>> D. >>> >>> On Sat, Feb 15, 2014 at 10:10 PM, Joe Hobart <nova@npgcable.com> wrote: >>>> >>>> These devices are primary standards; you don't need three; you probably >>>> don't even need two. If certain conditions are met, conditions you can >>>> check/verify, they will accurately generate the desired voltages. >>>> >>>> What you will probably want are at least three good zener type voltage >>>> standards and a constant temperature environment. The three will serve as a >>>> day to day standard and reality check on the JJA. And you need to really >>>> learn how to operate the JJA standard, so you can detect and correct any >>>> problems. >>>> >>>> Joe Hobart Flagstaff, Arizona >>>> >>>> >>>> On 2/15/2014 1:17 PM, Gordon DeWitte wrote: >>>>> Clearly need three (or some higher odd number) so they can vote... >>>>> >>>>> Gordon >>>>> >>>>> >>>>> On Sat, Feb 15, 2014 at 2:51 AM, Poul-Henning Kamp >>>>> <phk@phk.freebsd.dk>wrote: >>>>> >>>>>> In message >>>>>> <1392413149.25851.YahooMailNeo@web142405.mail.bf1.yahoo.com>, Randy >>>>>> Evans writes: >>>>>> >>>>>>> We'll all probably want a spare unit also. >>>>>> >>>>>> Two, how can you know which one fails, if you only have two ? >>>>>> >>>>>> -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@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. > _______________________________________________ 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. >

Thanks to the DOD and radio waves, accurate frequency is available at most places on Earth. SPRTs and more robust Reference PRTs have been available for many years. Frequency to one part in a thousand million is easy. Measuring temperature to 0.1 degree C is also easy; controlling temperature may not be as easy. What are the frequency, temperature, and other requirements for the "inexpensive" JVS systems NIST has been developing? How many similar JVS/JJA units does a major test equipment company like Agilent or Fluke have at any one location? Joe On 2/16/2014 12:00 PM, Chuck Harris wrote: > There are a host of things that will cause a JJA to be > off voltage... not the least of which is temperature and > frequency. > > Absent other standards to compare with your JJA, you are > really operating in the blind. > > The only major advantage to the JJA, and the reason it is > given primary standard status, is it relates voltage, to > frequency. If the pumping frequency is offset for some > reason, the voltage will be wrong by a similar amount. > > Do you imagine that NIST uses only one JJA to hold the > nation's standard volt? > > -Chuck Harris > > Tom Knox wrote: >> The physics of a properly run JJA will always produce the same result so you do >> not need additional units for comparison. That is the point of a world wide >> quantum voltage standard defined as K >> J-90 = 483 597.9 GHz/V . Just has the >> Hyperfine Transition of Cesium at about 9.192631770GHz is used to define the >> second. What is neat about the work NIST has done recently is that it has >> automated the System for ease of use and reduced the price to the point that it >> should see much wider use in day to day metrology. Having your Agilent 3458A >> calibrated on a JJA may not yield much difference over a Fluke 5730A cal, but >> once >> the meter has been run a few years characterizing the A to D converter and 10VAC >> range would only need to be done once and could substantially improve >> performance. >> I personally think that the face of calibration will change in coming years, >> rather then simple time based cal periods, instruments will contain complex >> environmental sensor packages that will constantly monitor the instruments >> environment . S o calibration will be based more on the instruments exposure to >> extreme conditions then simple time. I bet the act of shipping has more effect on >> cal then years sitting in a lab. So if for example a 3458A was put in an >> environmental chamber on a shaker table I am sure we find that up to a certain >> point enviromental conditions would have little effect on cal but at some point >> would have a major effect. Once documented the cals would be based more on >> environmental exposure. In addition I am sure some environmental effects on cal >> are repeatable and could be documented so if monitored they could be compensated >> for extending time between cals. So in the future you would see your instrument >> display "environment conditions exceeded" "cal require", with perhaps even a >> display of currently instrument uncertainty. This could change the face of >> calibration and become a multi-billion dollar industry. >> >> Thomas Knox >> >> >> >>> Date: Sun, 16 Feb 2014 07:06:18 -0700 From: nova@npgcable.com To: >>> volt-nuts@febo.com Subject: Re: [volt-nuts] JJA progress report >>> >>> >>> If Earth is subjected to a GRB strong enough to damage ground based >>> electronics, we are all going to have much more urgent problems than wondering >>> if a JVS is operating properly. Same for an EMP. Lightning, however, might >>> pose a more localized and serious threat. >>> >>> Part of your training as an expert operator will include techniques to dissuade >>> various critters from considering the JVS for their burial ceremonies. >>> >>> Carrying your best zener reference to the nearest facility with another JVS >>> would be less expensive than buying and operating a second or third system. >>> >>> Joe >>> >>> >>> On 2/16/2014 12:58 AM, cheater00 . wrote: >>>> How do you know the primary standard is not off? That is, how do you know it's >>>> still "primary"? Maybe a gamma ray burst from a supernova damaged some of the >>>> machinery inside, or a colony of crazy ants crawled in and died inside. >>>> >>>> D. >>>> >>>> On Sat, Feb 15, 2014 at 10:10 PM, Joe Hobart <nova@npgcable.com> wrote: >>>>> >>>>> These devices are primary standards; you don't need three; you probably >>>>> don't even need two. If certain conditions are met, conditions you can >>>>> check/verify, they will accurately generate the desired voltages. >>>>> >>>>> What you will probably want are at least three good zener type voltage >>>>> standards and a constant temperature environment. The three will serve as a >>>>> day to day standard and reality check on the JJA. And you need to really >>>>> learn how to operate the JJA standard, so you can detect and correct any >>>>> problems. >>>>> >>>>> Joe Hobart Flagstaff, Arizona >>>>> >>>>> >>>>> On 2/15/2014 1:17 PM, Gordon DeWitte wrote: >>>>>> Clearly need three (or some higher odd number) so they can vote... >>>>>> >>>>>> Gordon >>>>>> >>>>>> >>>>>> On Sat, Feb 15, 2014 at 2:51 AM, Poul-Henning Kamp >>>>>> <phk@phk.freebsd.dk>wrote: >>>>>> >>>>>>> In message >>>>>>> <1392413149.25851.YahooMailNeo@web142405.mail.bf1.yahoo.com>, Randy >>>>>>> Evans writes: >>>>>>> >>>>>>>> We'll all probably want a spare unit also. >>>>>>> >>>>>>> Two, how can you know which one fails, if you only have two ? >>>>>>> >>>>>>> -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@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. >> _______________________________________________ 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. > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2014.0.4259 / Virus Database: 3705/7097 - Release Date: 02/16/14 > >

How about the need for liquid He refrigeration? Will this bargain based JJA have a closed loop cooling system? Sure sounds interesting though. Tom ----- Original Message ----- From: "Joe Hobart" <nova@npgcable.com> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com> Sent: Sunday, February 16, 2014 2:54 PM Subject: Re: [volt-nuts] JJA progress report > Thanks to the DOD and radio waves, accurate frequency is available at most > places on Earth. SPRTs and more robust Reference PRTs have been available > for > many years. > > Frequency to one part in a thousand million is easy. Measuring > temperature to > 0.1 degree C is also easy; controlling temperature may not be as easy. > > What are the frequency, temperature, and other requirements for the > "inexpensive" JVS systems NIST has been developing? > > How many similar JVS/JJA units does a major test equipment company like > Agilent > or Fluke have at any one location? > > Joe > > > On 2/16/2014 12:00 PM, Chuck Harris wrote: >> There are a host of things that will cause a JJA to be >> off voltage... not the least of which is temperature and >> frequency. >> >> Absent other standards to compare with your JJA, you are >> really operating in the blind. >> >> The only major advantage to the JJA, and the reason it is >> given primary standard status, is it relates voltage, to >> frequency. If the pumping frequency is offset for some >> reason, the voltage will be wrong by a similar amount. >> >> Do you imagine that NIST uses only one JJA to hold the >> nation's standard volt? >> >> -Chuck Harris >> >> Tom Knox wrote: >>> The physics of a properly run JJA will always produce the same result so >>> you do >>> not need additional units for comparison. That is the point of a world >>> wide >>> quantum voltage standard defined as K >>> J-90 = 483 597.9 GHz/V . Just >>> has the >>> Hyperfine Transition of Cesium at about 9.192631770GHz is used to define >>> the >>> second. What is neat about the work NIST has done recently is that it >>> has >>> automated the System for ease of use and reduced the price to the point >>> that it >>> should see much wider use in day to day metrology. Having your Agilent >>> 3458A >>> calibrated on a JJA may not yield much difference over a Fluke 5730A >>> cal, but >>> once >>> the meter has been run a few years characterizing the A to D converter >>> and 10VAC >>> range would only need to be done once and could substantially improve >>> performance. >>> I personally think that the face of calibration will change in coming >>> years, >>> rather then simple time based cal periods, instruments will contain >>> complex >>> environmental sensor packages that will constantly monitor the >>> instruments >>> environment . S o calibration will be based more on the instruments >>> exposure to >>> extreme conditions then simple time. I bet the act of shipping has more >>> effect on >>> cal then years sitting in a lab. So if for example a 3458A was put in an >>> environmental chamber on a shaker table I am sure we find that up to a >>> certain >>> point enviromental conditions would have little effect on cal but at >>> some point >>> would have a major effect. Once documented the cals would be based more >>> on >>> environmental exposure. In addition I am sure some environmental effects >>> on cal >>> are repeatable and could be documented so if monitored they could be >>> compensated >>> for extending time between cals. So in the future you would see your >>> instrument >>> display "environment conditions exceeded" "cal require", with perhaps >>> even a >>> display of currently instrument uncertainty. This could change the face >>> of >>> calibration and become a multi-billion dollar industry. >>> >>> Thomas Knox >>> >>> >>> >>>> Date: Sun, 16 Feb 2014 07:06:18 -0700 From: nova@npgcable.com To: >>>> volt-nuts@febo.com Subject: Re: [volt-nuts] JJA progress report >>>> >>>> >>>> If Earth is subjected to a GRB strong enough to damage ground based >>>> electronics, we are all going to have much more urgent problems than >>>> wondering >>>> if a JVS is operating properly. Same for an EMP. Lightning, however, >>>> might >>>> pose a more localized and serious threat. >>>> >>>> Part of your training as an expert operator will include techniques to >>>> dissuade >>>> various critters from considering the JVS for their burial ceremonies. >>>> >>>> Carrying your best zener reference to the nearest facility with another >>>> JVS >>>> would be less expensive than buying and operating a second or third >>>> system. >>>> >>>> Joe >>>> >>>> >>>> On 2/16/2014 12:58 AM, cheater00 . wrote: >>>>> How do you know the primary standard is not off? That is, how do you >>>>> know it's >>>>> still "primary"? Maybe a gamma ray burst from a supernova damaged some >>>>> of the >>>>> machinery inside, or a colony of crazy ants crawled in and died >>>>> inside. >>>>> >>>>> D. >>>>> >>>>> On Sat, Feb 15, 2014 at 10:10 PM, Joe Hobart <nova@npgcable.com> >>>>> wrote: >>>>>> >>>>>> These devices are primary standards; you don't need three; you >>>>>> probably >>>>>> don't even need two. If certain conditions are met, conditions you >>>>>> can >>>>>> check/verify, they will accurately generate the desired voltages. >>>>>> >>>>>> What you will probably want are at least three good zener type >>>>>> voltage >>>>>> standards and a constant temperature environment. The three will >>>>>> serve as a >>>>>> day to day standard and reality check on the JJA. And you need to >>>>>> really >>>>>> learn how to operate the JJA standard, so you can detect and correct >>>>>> any >>>>>> problems. >>>>>> >>>>>> Joe Hobart Flagstaff, Arizona >>>>>> >>>>>> >>>>>> On 2/15/2014 1:17 PM, Gordon DeWitte wrote: >>>>>>> Clearly need three (or some higher odd number) so they can vote... >>>>>>> >>>>>>> Gordon >>>>>>> >>>>>>> >>>>>>> On Sat, Feb 15, 2014 at 2:51 AM, Poul-Henning Kamp >>>>>>> <phk@phk.freebsd.dk>wrote: >>>>>>> >>>>>>>> In message >>>>>>>> <1392413149.25851.YahooMailNeo@web142405.mail.bf1.yahoo.com>, Randy >>>>>>>> Evans writes: >>>>>>>> >>>>>>>>> We'll all probably want a spare unit also. >>>>>>>> >>>>>>>> Two, how can you know which one fails, if you only have two ? >>>>>>>> >>>>>>>> -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 >>>>>>>> phk@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. >>> _______________________________________________ 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. >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 2014.0.4259 / Virus Database: 3705/7097 - Release Date: 02/16/14 >> >> > _______________________________________________ > 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. >

Great, suppose the synthesizer that generates the pumping frequency from the stable frequency standard is malfunctioning, and producing a frequency off from the 483597.9 GHz/V that defines the JJA volt? Say it is providing 483597.902 GHz? Or, suppose that for some failure, one of the two leads that is transporting voltage out of the cryogenic section is finding itself at a different temperature than the other? Or suppose the terminals you are using to connect to the outside world have developed a difference in the alloy that connects them to the DUT? Without a pair of references you cannot tell if such a failure exists.. Without at least 3 such references, you can't tell which is the misbehaving reference. -Chuck Harris Joe Hobart wrote: > Thanks to the DOD and radio waves, accurate frequency is available at most > places on Earth. SPRTs and more robust Reference PRTs have been available for > many years. > > Frequency to one part in a thousand million is easy. Measuring temperature to > 0.1 degree C is also easy; controlling temperature may not be as easy. > > What are the frequency, temperature, and other requirements for the > "inexpensive" JVS systems NIST has been developing? > > How many similar JVS/JJA units does a major test equipment company like Agilent > or Fluke have at any one location? > > Joe > > > On 2/16/2014 12:00 PM, Chuck Harris wrote: >> There are a host of things that will cause a JJA to be >> off voltage... not the least of which is temperature and >> frequency. >> >> Absent other standards to compare with your JJA, you are >> really operating in the blind. >> >> The only major advantage to the JJA, and the reason it is >> given primary standard status, is it relates voltage, to >> frequency. If the pumping frequency is offset for some >> reason, the voltage will be wrong by a similar amount. >> >> Do you imagine that NIST uses only one JJA to hold the >> nation's standard volt? >> >> -Chuck Harris

As has been satid before, you only need one JJA plus two or more stable (over the time betwwen checks) working references and a voltage measuring device of sufficent resolution to compare them.   Robert G8RPI. ________________________________ From: Chuck Harris <cfharris@erols.com> To: Discussion of precise voltage measurement <volt-nuts@febo.com> Sent: Sunday, 16 February 2014, 20:53 Subject: Re: [volt-nuts] JJA progress report Great, suppose the synthesizer that generates the pumping frequency from the stable frequency standard is malfunctioning, and producing a frequency off from the 483597.9 GHz/V that defines the JJA volt?  Say it is providing 483597.902 GHz? Or, suppose that for some failure, one of the two leads that is transporting voltage out of the cryogenic section is finding itself at a different temperature than the other? Or suppose the terminals you are using to connect to the outside world have developed a difference in the alloy that connects them to the DUT? Without a pair of references you cannot tell if such a failure exists.. Without at least 3 such references, you can't tell which is the misbehaving reference. -Chuck Harris Joe Hobart wrote: > Thanks to the DOD and radio waves, accurate frequency is available at most > places on Earth.  SPRTs and more robust Reference PRTs have been available for > many years. > > Frequency to one part in a thousand million is easy.  Measuring temperature to > 0.1 degree C is also easy; controlling temperature may not be as easy. > > What are the frequency, temperature, and other requirements for the > "inexpensive" JVS systems NIST has been developing? > > How many similar JVS/JJA units does a major test equipment company like Agilent > or Fluke have at any one location? > > Joe > > > On 2/16/2014 12:00 PM, Chuck Harris wrote: >> There are a host of things that will cause a JJA to be >> off voltage... not the least of which is temperature and >> frequency. >> >> Absent other standards to compare with your JJA, you are >> really operating in the blind. >> >> The only major advantage to the JJA, and the reason it is >> given primary standard status, is it relates voltage, to >> frequency.  If the pumping frequency is offset for some >> reason, the voltage will be wrong by a similar amount. >> >> Do you imagine that NIST uses only one JJA to hold the >> nation's standard volt? >> >> -Chuck Harris _______________________________________________ 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.

You still are not getting it. If your JJA hasn't been compared to another JJA, you have no way of telling that it is truly working properly. Once you have compared it to other JJA's, and have determined that it is correct, you should be able to keep it in check by comparing it to other high quality references, but before that you are just guessing. -Chuck Harris Robert Atkinson wrote: > As has been satid before, you only need one JJA plus two or more stable (over the > time betwwen checks) working references and a voltage measuring device of > sufficent resolution to compare them. > > Robert G8RPI.