Out of Calibration vs. Out of Tolerance - Calibration Definitions

I am working on cleaning up a quality procedure covering cal of test and measuring equipment. Included in this is a form titled, "Instrument Out of Calibration Notification", which is to be filled out when a piece of test equipment is found Out of Tolerance. The two terms are often used in conjunction, but, should they be? Out of calibration can be used to describe an out of tolerance condition but it can also be used to describe when a piece of equipment has passed it's cal due date and is therefore, out of calibration. Does anyone have an "official" definition of the term "out of calibration"? I have reviewed various regulations, etc (FDA, cGmp) and I don't see out of calibration stated anywhere but I do see out of tolerance.

Re: out of calibration vs. out of tolerance

bigjrfan said:

I am working on cleaning up a quality procedure covering cal of test and measuring equipment. Included in this is a form titled, "Instrument Out of Calibration Notification", which is to be filled out when a piece of test equipment is found Out of Tolerance. The two terms are often used in conjunction, but, should they be? Out of calibration can be used to describe an out of tolerance condition but it can also be used to describe when a piece of equipment has passed it's cal due date and is therefore, out of calibration. Does anyone have an "official" definition of the term "out of calibration"? I have reviewed various regulations, etc (FDA, cGmp) and I don't see out of calibration stated anywhere but I do see out of tolerance.

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chan

Welcome to the Cove.

I don't think you'll find any universally accepted or standardized definitions. The apparent confusion of the form title could be remedied by changing the title to "Instrument out of Tolerance Notice," but if the people who use the form know what it's for, I'm not sure I'd bother with it. Whether a device is overdue for calibration or actually known to be out of tolerance, the result (taking the device out of service and calibrating it) will probably be the same.

Re: out of calibration vs. out of tolerance

Welcome! We have some great cal/metrology experts here to help...

I'd suggest that you're correct, most people use the terms interchangeably. I've used out of tol worksheets, for situations you describe, not for missing a due date, preferring to use a 'past due' notice.

You might want to check on the 'GUM' or more correctly titled, Vocabulary of Intl Measurement...

Re: out of calibration vs. out of tolerance

This form is referenced in many other calibration procedures so if I were to change the title, I would also have to change form name in all other procedures. I wanted to see what others thought on the subject. I hadn't ever posted a question or reply on this site but have been coming here for many years looking for answers to my questions or just to read up on other people's troubles. Thanks for welcoming me to the site.

You are welcome! Do bring your experiences as well! Yes, you'll have to make that change, but that's good too!

FWIW... I agree totally with Jim and Andy.

While a room of intellectual metrologists could argue the point into submission , in the end I'm not sure the terminology is that relevant.

I would just be consistent, and assure that everyone in the organization understands precisely what the form is and what it represents.

Regardless of what you call it, the users need to understand the purpose of the form when they receive it, what actions they should take, and what to do with it when they are done.

in my experience; we should be checking calibration status before use including effective date and calibrated or not?

when the discrepancies is coming, firstly we need to use quality tools to analysis root cause such as 4M1E,5WHY and so on

certainly, out of calibration is also reason has cause out of tolerance

bigjrfan said:

I am working on cleaning up a quality procedure covering cal of test and measuring equipment. Included in this is a form titled, "Instrument Out of Calibration Notification", which is to be filled out when a piece of test equipment is found Out of Tolerance. The two terms are often used in conjunction, but, should they be? Out of calibration can be used to describe an out of tolerance condition but it can also be used to describe when a piece of equipment has passed it's cal due date and is therefore, out of calibration. Does anyone have an "official" definition of the term "out of calibration"? I have reviewed various regulations, etc (FDA, cGmp) and I don't see out of calibration stated anywhere but I do see out of tolerance.

Click to expand...

How will you find out that the equipment is out of tolerance ?
It is simple if the deviation is large and is obvious. But what if the deviation is small and you begin to accept bad parts or reject good parts, leading to some non conformance or customer complaint., and further leading to some RC analysis. If the RC analysis (the big maze always) is right, then you will end up tracking the equipment which is out of tolerance (but within calibration). This could cost the company dearly.
An out of calibration equipment on the other hand may be in tolerance but your system prompts you to calibrate again and to not use after the due period until re-calibrated to good.
It is for this that the ISO standard is very sensitive and asks the organization with a shall requirement the following:
Where necessary to ensure valid results, measuring equipment shall
a) be calibrated or verified, or both, at specified intervals, or prior to use, against measurement standards traceable to international or national measurement standards; where no such standards exist, the basis used for calibration or verification shall be recorded (see 4.2.4);
b) be adjusted or re-adjusted as necessary;
c) have identification in order to determine its calibration status;
d) be safeguarded from adjustments that would invalidate the measurement result;
e) be protected from damage and deterioration during handling, maintenance and storage.
Specified interval is NOT ANNUAL and MUST BE DETERMINED by the organization
d) and e) are also a shall requirement and must be strictly respected for measurement assurance.
Measurement assurance is within Quality assurance and a QMS aims to enhance Quality assurance.