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Need to Estimate Uncertainty for some simple measurements

Need to Estimate Uncertainty for some simple measurements

Need to Estimate Uncertainty for some simple measurements

(OP)
Does anyone know of a spreadsheet (Excel)?? or other source for estimating uncertainty in two (2) types of measurements:
Voltage readings with a Digital Fluke Meter
and
Force measurements with a Chatillan Digital Force Meter?
I am looking for a simple method to quantify the uncertainty for approximately 50 readings of ea. type to satisfy an ISO audit.

RE: Need to Estimate Uncertainty for some simple measurements

Uncertaincy?

If you have analysis toolpack installed (assuming EXECEL) the choose "descriptive statistic". The function will give you mean, std. dev and some other info. Usually +/-3 sigma is considered the range that any measurement should be within (99.96 i think it would cover in the normal distribution).

If your uncertian on propability/statistics the help function isnt much help. You gotta know what your dooing up front.

Best Regards

Morten

RE: Need to Estimate Uncertainty for some simple measurements

You might want to perform a "Gauge R&R" study, which is a good way of examining the reliability and repeatability of a test.

Cheers

Greg Locock

RE: Need to Estimate Uncertainty for some simple measurements

After spending 5 years in a Quality lab, I would definitly agree with GregLocock!

RE: Need to Estimate Uncertainty for some simple measurements

For Measurement Uncertainty you should reference TN 1297 from NIST and EAL-R2 "Guide to the Expression of Uncertainty in Measurement" (based on the GUM) replaced by EA-4/02 "Expression of the Uncertainty of Measurement in Calibration".  Coverage factor is k=2 for measurement uncertainty according to the GUM for calibration equipment.  These documents can be downloaded, either from NIST web page or the EAL web page.  If your are trying to determine uncertainty based on QS-9000 4.10/4.11 requirements for calibration equipment then you should reference the above documents.  If the equipment is used in the MFR environment, non-calibration, then Gage R&R is an option.

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