Acceptance Criteria for Calibration by an External Calibration Laboratory

We are doing calibration at external agency.After calibration process,we need to verify the certify the calibration record for suitability of use.

We can accept the intruments based on the tolerance of our process.

Can anyone send me the standard acceptance criteria for accepting the instruments

What equipment are you having calibrated by an external laboratory?

The best criteria for acceptance of the report is ISO/IEC 17025:2005 Clauses 5.10.2, 5.10.4, and the remaining sub-Clauses of 5.10 as appropriate.

Hope this helps.

Thanks for your reply. I am looking for acceptability error based on the acceptance std.

Thanks for your reply.

We are calibrating Digital vernier caliper, Micrometer, Thread plug gauge, Thread ring gauge, Vernier height gauge.

I'm not sure I follow what is the question, here.

If I understand, you are sending instruments off to an external lab for calibration. When they return, you are wondering what acceptance criteria to use for the instruments. Is that accurate?

If so, what about using mfg. specifications or even your own process tolerance limits for acceptance? Whichever acceptance criteria you use, it should be documented.

Dear All

Could you please help me to get the process for acceptance criteria or please confirm what I decided

Option 1 : I should look for what is declared permissible error for the specified range & if my least tolerance is less that that error then I should accept instrument.

Option 2 : Or I should go with 1/3 rd criteria of the least tolerance I am going to measure by that instrument & if indicated error by 3rd party is less than the 1/3rd of tolerance then accept the instrument.

e.g Least tolerance to be measured by instrument +/-0.02 & Error after calibration 30micron but per criteria set I will accept 1/3rd of least tolerance i.e 66 micron then I should accept the instrument for further use.

Please confirm or share the good acceptance criteria

rizsa said:

Please confirm or share the good acceptance criteria

Click to expand...

"Good" acceptance criteria, in the long run, is set by your company.

That being said...I would go at absolute least to 1/4 of your lowest tolerance...preferably 1/10.

When you do a GRR using these gages, if your error due to equipment variation is 1/4 of your tolerance being measured...it's going to be hard to defend the results of the GRR.

Equipment variation and error are not the same thing...but do consider both when determining the utility of the gage's performance.

At the end of the day...the question you have to be comfortable answering is, "Why do I trust this gage to tell good parts from bad parts?"
Both you and your customers have to be comfortable with your answer to this question.

Each device has different acceptance criteria

My humble opinion is that you may be getting things a bit backwards here.

You should be determining the tolerance ratio from your lab before you send your equipment there, not when it gets back. As part of the "contract review" process you must do the due diligence to determine if the lab's capabilities are equal to your requirements, otherwise find another lab. This is covered in section 4.4 of ISO 17025:2005.

As far as the acceptance criteria for the calibration results, that is more a check to see if the results provided meet what you requested from the lab. If there are errors, omissions, tests requested but not performed, results that have a different accuracy ratio from the ones contracted for, etc. then you go back to the lab to get these corrected and resolved. Basically you are documenting that you got what you expected, and it meets your requirements.