Think twice about those Vishay metal film resistors... they have known stability problems (particularly concerning humidity). Also they can have problems meeting their own specs. There is an active thread of eevblog.com concerning the issue. Consensus seems to be precision wire wound resistors are a better choice. -------------------- These will be replaced by 2 vishay 0.01% resistors which are hopefully more stable.

What is the group consensus on Vishay metal foil? Thanks Thomas Knox > From: holrum@hotmail.com > To: volt-nuts@febo.com > Date: Sat, 16 May 2015 18:22:22 +0000 > Subject: [volt-nuts] How accurate is a fluke after 9 years > > Think twice about those Vishay metal film resistors... they have known stability problems (particularly concerning humidity). Also they can have problems meeting their own specs. There is an active thread of eevblog.com concerning the issue. Consensus seems to be precision wire wound resistors are a better choice. > > -------------------- > These will be replaced by 2 vishay 0.01% resistors which are hopefully more stable. > _______________________________________________ > 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.

IMHO: Vishay metal-foil resistors are very good, but *ONLY* if you get them in a hermetic package. Depending on where you are in the world, this can be rather expensive [more or less]. Precision wire-wound resistors made with with low TCR Evanohm wire *THAT ARE PROPERLY WELDED* are the next best thing, and they don't cost you your first born...

 Pada Minggu, 17 Mei 2015 2:11, Ken Peek <ken.peek@diligentminds.com> menulis:

Hi All,What about Edward G Pettis resistor are they include in *THAT ARE PROPERLY WELDED* Pada Minggu, 17 Mei 2015 2:11, Ken Peek <ken.peek@diligentminds.com> menulis: IMHO:  Vishay metal-foil resistors are very good, but *ONLY* if you get them in a hermetic package.  Depending on where you are in the world, this can be rather expensive [more or less].  Precision wire-wound resistors made with with low TCR Evanohm wire *THAT ARE PROPERLY WELDED* are the next best thing, and they don't cost you your first born... _______________________________________________ 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.

  Pada Minggu, 17 Mei 2015 2:11, Ken Peek <ken.peek@diligentminds.com> menulis:

I have VPG hermetic foil resistors that drifted 0.2ppm/year (verified in cal lab). temp co. arround room temp <0,2ppm/k. my personal opinion, they are the best resistors for stability that you can purchse as a standard list item. Mine were < 40usd (4-wire, 0.1%, in reality they are better 0.01%). 2-wire types are probably cheaper. you cannot use standard foil resistors, they drift due to humidity, some 10 ppm easily pa. I would think Edward Petties do drift as well, most likely onsiderably more than the heremtic resistors, but probably less than vpg epoxy foil,(there is no drift spec against time from him), since his are not hermetic. And also, typically his temp drift is worse (1-3ppm/K versus <0,5). Adrian > Gesendet: Sonntag, 17. Mai 2015 um 03:40 Uhr > Von: "Anton Moehammad via volt-nuts" <volt-nuts@febo.com> > An: "Ken.Peek@DiligentMinds.com" <Ken.Peek@DiligentMinds.com>, "Discussion of precise voltage measurement" <volt-nuts@febo.com> > Betreff: [volt-nuts] Bls: How accurate is a fluke after 9 years > > Hi All,What about Edward G Pettis resistor are they include in *THAT ARE PROPERLY WELDED* > > > > Pada Minggu, 17 Mei 2015 2:11, Ken Peek <ken.peek@diligentminds.com> menulis: > > > IMHO:  Vishay metal-foil resistors are very good, but *ONLY* if you get > them in a hermetic package.  Depending on where you are in the world, > this can be rather expensive [more or less].  Precision wire-wound > resistors made with with low TCR Evanohm wire *THAT ARE PROPERLY WELDED* > are the next best thing, and they don't cost you your first born... > > > _______________________________________________ > 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. >

   Pada Minggu, 17 Mei 2015 2:11, Ken Peek <ken.peek@diligentminds.com> menulis:
 

Hello Adrian, which actual type of resistor did you use. And from where did you order it? For which quantity is the 40 usd price? (single piece?) I guess it was one of the hzseries of vishay. right? Perhaps a Y4725 (VHA512Z?) http://www.vishaypg.com/docs/63120/hzseries.pdf Was it including PMO? With best regards Andreas Am 17.05.2015 um 18:16 schrieb acbern@gmx.de: > I have VPG hermetic foil resistors that drifted 0.2ppm/year (verified in cal lab). temp co. arround room temp <0,2ppm/k. my personal opinion, they are the best resistors for stability that you can purchse as a standard list item. Mine were < 40usd (4-wire, 0.1%, in reality they are better 0.01%). 2-wire types are probably cheaper. > you cannot use standard foil resistors, they drift due to humidity, some 10 ppm easily pa. > I would think Edward Petties do drift as well, most likely onsiderably more than the heremtic resistors, but probably less than vpg epoxy foil,(there is no drift spec against time from him), since his are not hermetic. And also, typically his temp drift is worse (1-3ppm/K versus <0,5). > > Adrian > >> Gesendet: Sonntag, 17. Mai 2015 um 03:40 Uhr >> Von: "Anton Moehammad via volt-nuts" <volt-nuts@febo.com> >> An: "Ken.Peek@DiligentMinds.com" <Ken.Peek@DiligentMinds.com>, "Discussion of precise voltage measurement" <volt-nuts@febo.com> >> Betreff: [volt-nuts] Bls: How accurate is a fluke after 9 years >> >> Hi All,What about Edward G Pettis resistor are they include in *THAT ARE PROPERLY WELDED* >> >> >> >> Pada Minggu, 17 Mei 2015 2:11, Ken Peek <ken.peek@diligentminds.com> menulis: >> >> >> IMHO: Vishay metal-foil resistors are very good, but *ONLY* if you get >> them in a hermetic package. Depending on where you are in the world, >> this can be rather expensive [more or less]. Precision wire-wound >> resistors made with with low TCR Evanohm wire *THAT ARE PROPERLY WELDED* >> are the next best thing, and they don't cost you your first born... >> >> >> _______________________________________________ >> 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.

   Pada Minggu, 17 Mei 2015 2:11, Ken Peek <ken.peek@diligentminds.com> menulis:
 

hi andreas, yes, it was a vha512 (maybe 516, but dont think so, dont have data handy). I ordered it from their berlin area based distributor (powertron). I ordered a couple, but different values, so it was single piece price. was some time ago, so price may have increased by now. adrian > Gesendet: Sonntag, 17. Mai 2015 um 22:00 Uhr > Von: "Andreas Jahn" <Andreas_-_Jahn@t-online.de> > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com> > Betreff: Re: [volt-nuts] Bls: How accurate is a fluke after 9 years > > Hello Adrian, > > which actual type of resistor did you use. > And from where did you order it? > For which quantity is the 40 usd price? (single piece?) > > I guess it was one of the hzseries of vishay. right? > Perhaps a Y4725 (VHA512Z?) > http://www.vishaypg.com/docs/63120/hzseries.pdf > Was it including PMO? > > With best regards > > Andreas > > Am 17.05.2015 um 18:16 schrieb acbern@gmx.de: > > I have VPG hermetic foil resistors that drifted 0.2ppm/year (verified in cal lab). temp co. arround room temp <0,2ppm/k. my personal opinion, they are the best resistors for stability that you can purchse as a standard list item. Mine were < 40usd (4-wire, 0.1%, in reality they are better 0.01%). 2-wire types are probably cheaper. > > you cannot use standard foil resistors, they drift due to humidity, some 10 ppm easily pa. > > I would think Edward Petties do drift as well, most likely onsiderably more than the heremtic resistors, but probably less than vpg epoxy foil,(there is no drift spec against time from him), since his are not hermetic. And also, typically his temp drift is worse (1-3ppm/K versus <0,5). > > > > Adrian > > > >> Gesendet: Sonntag, 17. Mai 2015 um 03:40 Uhr > >> Von: "Anton Moehammad via volt-nuts" <volt-nuts@febo.com> > >> An: "Ken.Peek@DiligentMinds.com" <Ken.Peek@DiligentMinds.com>, "Discussion of precise voltage measurement" <volt-nuts@febo.com> > >> Betreff: [volt-nuts] Bls: How accurate is a fluke after 9 years > >> > >> Hi All,What about Edward G Pettis resistor are they include in *THAT ARE PROPERLY WELDED* > >> > >> > >> > >> Pada Minggu, 17 Mei 2015 2:11, Ken Peek <ken.peek@diligentminds.com> menulis: > >> > >> > >> IMHO: Vishay metal-foil resistors are very good, but *ONLY* if you get > >> them in a hermetic package. Depending on where you are in the world, > >> this can be rather expensive [more or less]. Precision wire-wound > >> resistors made with with low TCR Evanohm wire *THAT ARE PROPERLY WELDED* > >> are the next best thing, and they don't cost you your first born... > >> > >> > >> _______________________________________________ > >> 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. > > _______________________________________________ > 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. >

 Pada Senin, 18 Mei 2015 3:25, "acbern@gmx.de" <acbern@gmx.de> menulis:

Hi All, in the Vishay web I found "a better in spec" resistor than  vha512, could somebody give a comment ? http://www.vishaypg.com/docs/63120/hzseries.pdfThey also offer non standard value, anybody has experience in Vishay non standard value ? Thank You Pada Senin, 18 Mei 2015 3:25, "acbern@gmx.de" <acbern@gmx.de> menulis: hi andreas, yes, it was a vha512 (maybe 516, but dont think so, dont have data handy). I ordered it from their berlin area based distributor (powertron). I ordered a couple, but different values, so it was single piece price. was some time ago, so price may have increased by now. adrian > Gesendet: Sonntag, 17. Mai 2015 um 22:00 Uhr > Von: "Andreas Jahn" <Andreas_-_Jahn@t-online.de> > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com> > Betreff: Re: [volt-nuts] Bls:  How accurate is a fluke after 9 years > > Hello Adrian, > > which actual type of resistor did you use. > And from where did you order it? > For which quantity is the 40 usd price? (single piece?) > > I guess it was one of the hzseries of vishay. right? > Perhaps a Y4725 (VHA512Z?) > http://www.vishaypg.com/docs/63120/hzseries.pdf > Was it including PMO? > > With best regards > > Andreas > > Am 17.05.2015 um 18:16 schrieb acbern@gmx.de: > > I have VPG hermetic foil resistors that drifted 0.2ppm/year (verified in cal lab). temp co. arround room temp <0,2ppm/k. my personal opinion, they are the best resistors for stability that you can purchse as a standard list item. Mine were < 40usd (4-wire, 0.1%, in reality they are better 0.01%). 2-wire types are probably cheaper. > > you cannot use standard foil resistors, they drift due to humidity, some 10 ppm easily pa. > > I would think Edward Petties do drift as well, most likely onsiderably more than the heremtic resistors, but probably less than vpg epoxy foil,(there is no drift spec against time from him), since his are not hermetic. And also, typically his temp drift is worse (1-3ppm/K versus <0,5). > > > > Adrian > > > >> Gesendet: Sonntag, 17. Mai 2015 um 03:40 Uhr > >> Von: "Anton Moehammad via volt-nuts" <volt-nuts@febo.com> > >> An: "Ken.Peek@DiligentMinds.com" <Ken.Peek@DiligentMinds.com>, "Discussion of precise voltage measurement" <volt-nuts@febo.com> > >> Betreff: [volt-nuts] Bls:  How accurate is a fluke after 9 years > >> > >> Hi All,What about Edward G Pettis resistor are they include in *THAT ARE PROPERLY WELDED* > >>  > >> > >> > >>      Pada Minggu, 17 Mei 2015 2:11, Ken Peek <ken.peek@diligentminds.com> menulis: > >>    > >> > >>  IMHO:  Vishay metal-foil resistors are very good, but *ONLY* if you get > >> them in a hermetic package.  Depending on where you are in the world, > >> this can be rather expensive [more or less].  Precision wire-wound > >> resistors made with with low TCR Evanohm wire *THAT ARE PROPERLY WELDED* > >> are the next best thing, and they don't cost you your first born... > >> > >> > >> _______________________________________________ > >> 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. > > _______________________________________________ > 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.

it is this resistor, in its z-foil version. they can be ordered from vpg distributors also in small qty (some may have a min. order value), lead time is usually pretty high. > Gesendet: Montag, 18. Mai 2015 um 02:39 Uhr > Von: "Anton Moehammad via volt-nuts" <volt-nuts@febo.com> > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com> > Betreff: [volt-nuts] Bls: Bls: How accurate is a fluke after 9 years > > Hi All, > in the Vishay web I found "a better in spec" resistor than  vha512, could somebody give a comment ? > http://www.vishaypg.com/docs/63120/hzseries.pdfThey also offer non standard value, anybody has experience in Vishay non standard value ? > > Thank You > >

The 5700A5720A verification test lists a maximum deviation from nominal on the resistance ranges. Is there any information on how well Fluke's hybrid resistors are maintaining their specs over the lifetime of the calibrator? Anyone have access to long term records of the resistance values? Todd On Mon, May 18, 2015 at 2:13 AM, <acbern@gmx.de> wrote: > it is this resistor, in its z-foil version. > they can be ordered from vpg distributors also in small qty (some may have > a min. order value), lead time is usually pretty high. > > > > Gesendet: Montag, 18. Mai 2015 um 02:39 Uhr > > Von: "Anton Moehammad via volt-nuts" <volt-nuts@febo.com> > > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com> > > Betreff: [volt-nuts] Bls: Bls: How accurate is a fluke after 9 years > > > > Hi All, > > in the Vishay web I found "a better in spec" resistor than vha512, > could somebody give a comment ? > > http://www.vishaypg.com/docs/63120/hzseries.pdfThey also offer non > standard value, anybody has experience in Vishay non standard value ? > > > > Thank You > > > > > _______________________________________________ > 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. >