PMEL Forum

K Sections => K1/8 - DC/Low Frequency => Topic started by: scottbp on 06-22-2012 -- 11:42:44

Title: Preparing a HP 3458A uncertainty budget
Post by: scottbp on 06-22-2012 -- 11:42:44
Has anybody here ever had to prepare an uncertainty budget for an HP 3458A multimeter for their scope of accreditation? I have a question... What is the proper way to prepare the budget? How did you set up your type B analysis? Did you add the uncertainty of the calibrator you calibrated it with to the absolute specification, or did you figure it into the budget some other way?  :?

I compare my 3458A best measurement capability summary with other people's scopes of accreditation to make sure I'm at least in the ballpark and not overstating it (i.e. claiming a tighter uncertainty than NIST) or shooting myself in the foot (claiming worse uncertainties than a 3-1/2 digit DMM).

I do it one way and the auditor tells me I'm doing it wrong, so I fix it, then next time a different auditor tells me I'm doing it wrong for a different reason, and on and on... Preparing uncertainty budgets for a scope of accreditation is sorta like taking a math test one year and getting it wrong, then taking the exact same test again a month later and putting the "corrected" answers only for it to be wrong again...
Title: Re: Preparing a HP 3458A uncertainty budget
Post by: RFCAL on 06-22-2012 -- 13:05:22
what software are you using? I have several excell spreadsheets I can send you. Let me know if you need them and where to send them.
Title: Re: Preparing a HP 3458A uncertainty budget
Post by: beadwork on 06-25-2012 -- 05:44:33
The Uncertainty Toolbox from Quametec is a really great!
Title: Re: Preparing a HP 3458A uncertainty budget
Post by: RFCAL on 06-25-2012 -- 07:51:21
Did you get the spreadsheet I seny you?
Title: Re: Preparing a HP 3458A uncertainty budget
Post by: Boatkook on 06-26-2012 -- 18:25:12
Thanks beadwork for the heads up on Uncertainty Toolbox.  We're using it here at JSC.