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 <[email protected]> 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 > > >[email protected] >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" <[email protected]> >To: Discussion of precise voltage measurement <[email protected]>; >Discussion of precise voltage measurement <[email protected]> >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. > > >http://us.flukecal.com/literature/articles-and-education/temperature-calibration/papers-articles/comparison-ansincsl-z540-1?geoip=1 > >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 -- [email protected] >To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >and follow the instructions there. >_______________________________________________ >volt-nuts mailing list -- [email protected] >To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >and follow the instructions there. > >_______________________________________________ >volt-nuts mailing list -- [email protected] >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 -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
