02:39 Jan-17-2003 Uli Mletzko R & D, Retired Germany, Joined Nov 1998 89
Re: ISO 17025 : EN ISO 17025 standard for accreditation testing lab require : that uncertainty measurement. Have any body are there has this info.
To solve the problem, we are using the different terms 'Nondestructive TESTING = non-quantitative NDT' and 'Nondestructive MEASURING = quantitative NDT'.
If you are applying only standard techniques like radiography, ultrasonics for flaw detection, etc., you have to convince the auditor, that this is 'TESTING' and not 'MEASURING', and that therefore ISO 17025 is not applicable.
On the other side, if you are doing wall thickness measuring by ultrasonics, hardening depth measuring by eddy current, corrosion depth measuring by radiography, etc., you or your level-3-man has to know about the accuracy. But this is not a simple task (depending on frequency, film graininess, etc.).
Sometimes, if you have new equipment, or if your equipment is maintenanced periodically by the manufacturer, then the manufacturer possibly could supply you with accuracy data or with a data sheet.
Regards Uli Mletzko, MPA/NDT, University of Stuttgart, Germany
Re: ISO 17025 reply by Udo Schlengermann firstname.lastname@example.org:
Standard EN ISO/IEC 17025 is important for all kind of testing and calibration laboratories.
As much as uncertainty is concerned, please read chapter 5.4.6: Estimation of uncertainty of measurement, especially the three notes. note 1 says that the degree of estimation of uncertainty should be chosen depending on the requirements of the tests, the requirements of the client and depending on existing limits. note 2 says, that if the test method is well definded (including uncertainty)there is no further need for validation of uncertainty by the test laboratory applying this method. note 3 gives a hint for further information to ISO 5725 and the "Guide to the expression of uncertainty in measurement" published by BIMP, IEC, ISO et al.
so there is a wide for for agreements with clients and auditors in relation to specific test methods.