How to Evaluate a Calibration Report Certificate

[silver ring]

Hi,

Measuring devices are sent to calibration. After the calibration is completed, measuring devices are returned back together with their calibration certificates. How are we going to evaluate these certificates. What are the critical points to look for and judge the usability of the measuring equipment?

Thanks

 

[phloQS]

Re: How to Evaluate a Calibration Certificate

Calibration depends on type of measuring device. The accuracy, the precision and the nominal value could be some of the information. Information on the kind of calibration nominals could be another information. Basics like who did it, when was it performed and when is next calibration required should also be in place.

regards

phloQS

 

[MantleMickey]

Re: How to Evaluate a Calibration Certificate

When I get back gaging, I look for CALIBRATION RESULT-PASSED.
Next, I look at the ranges of the calibration checks.
Example-standard is .00200, tolerance is + .00210, - .00190.
My gage measured AS FOUND .00204, within this range.
I check each measurement the same way, to ensure all ranges
are in spec. I also make sure gages were calibrated to ISO/IEC 17025
If all looks good on the cert of calibration, I check mark and initial the
report to show it was reviewed. Good luck.

 

[BradM]

Re: How to Evaluate a Calibration Certificate

Aside from the great responses given...

• Date calibration was performed
• N.I.S.T. traceability
• procedure used for verification
• as-found/ as-left data (if requested)
• Technician name
• Uncertainty/ statement of uncertainty
• Company name/ organization that actually performed the calibration (in the event the service was outsourced).
• I evaluate the data and compare to previous results. Are we calibrating too often/ not often enough? (To me... as-found/ as-left data pays for itself with the management information it provides.)
• Is the device suitable for its current use/purpose?
• If the device was found Out Of Tolerance, the magnitude of the error is useful in investigating any potential process impact.

I can't think of no more right now.

 

[Hershal]

Re: How to Evaluate a Calibration Certificate

One thing to watch for, if the cal lab is accredited, then the accreditation information. It is possible that for that information there will be an additional charge.

For traceability, in the US it is common to claim NIST traceability, though not required if a different NMI is providing the traceability. If outside the US, then a different NMI is the norm.

Hope this helps.

 

[jimatsntc]

Re: How to Evaluate a Calibration Certificate

I agree with everyone above....and one more thing you need check is the standard they used to calibrate your equipment... every lab. shall indicate the referencd standard used... checked the spec. if that is suitable or good enough to use as a standard...
Good luck...

 

[barkranch]

Re: How to Evaluate a Calibration Certificate

Can anyone please help me understand the information that should be reported on a calibration report? I understand what basic information must be documented on the report. What I am struggling with is how do I determine the accuracy of the instruments used to calibrate my gages (thread rings for example)? The reports I receive list the measuring instruments used to calibrate the thread rings and their identification/calibration due dates but it does not report their accuracy. Naturally, the measuring instruments accuracy should be greater than the gage it is calibrating. I had an auditor ask me how do I verify the measuring instruments accuracy is greater then the gage it is measuring and I didn't know how to respond. I work for a medical device manufacturer and we are certified to ISO 13485. Any response is greatly appreciated.

 

[Sean Kelley]

Re: How to Evaluate a Calibration Certificate

I would like to add that the scope of the 17025 certification needs to be verified. We had a finding in the past that one our our pyrometers measured to 2100 degrees and the company performing calibration was only certified up to 1800 so this pyrometer was out of their scope.

Another example: if they are calibrating your micrometers make sure their scope includes micrometers of that range such as 0-1", 1-2", etc. They may be able to do small micrometers under their scope but when your get to a 48" they may not be certified to be doing this work.

 

[JRKH]

Re: How to Evaluate a Calibration Certificate

Can anyone please help me understand the information that should be reported on a calibration report? I understand what basic information must be documented on the report. What I am struggling with is how do I determine the accuracy of the instruments used to calibrate my gages (thread rings for example)? The reports I receive list the measuring instruments used to calibrate the thread rings and their identification/calibration due dates but it does not report their accuracy. Naturally, the measuring instruments accuracy should be greater than the gage it is calibrating. I had an auditor ask me how do I verify the measuring instruments accuracy is greater then the gage it is measuring and I didn't know how to respond. I work for a medical device manufacturer and we are certified to ISO 13485. Any response is greatly appreciated.

Sorry that I don't have a reply for you...but if I may suggest - it might be better to make this a new thread - you're likely to get a wider response than piggy-backing it here.

James