posted 28 February 2001 12:04 PM               

Thank ya all for your help.

posted 01 March 2001 03:24 PM               

Another might be tape rules in some shops. They have folks compare them to a steel ruler on the wall once a month, for example. That's verification.

posted 02 March 2001 09:59 AM               

Marc,

I used to think the same thing, and write my systems using this approach. Then I had a gaging wiz for an auditor who informed me that the key was traceability, not necessarily adjustment. If the "verification" was done with a traceable standard, it qualified as a "calibration".

I found this more than confusing, but if you consider what the cal houses do, it kind of makes sense. If they check the gage with a traceable standard and its OK, it's still considered calibration. If they make an adjustment, they check again after to make sure the adjustment was correct. Now it's an adjust and calibrate.

I still don't have clear in my mind what verification is with the possible exception of a check without traceability (perhaps only in terms of the paper trail).

BTW, even though I had that discussion with that auditor and came away from it confused, I still consider and write systems using the thought process that you describe.

posted 02 March 2001 10:49 AM               

I recently had an SGS auditor inform me that verification is a check of the instrument done outside of the normal calibration system. i.e. Scales are calibrated on quarterly basis. Every morning an operator uses a "weight" that is close to the mid point of the normal operating range of the scale to assure that the scale is "within tolerance". A simple record of who, and when is kept. If the scale is "in tolerance" nothing happens. If the scale is "out of tolerance", calibration services is notified. Tolerance is defined as something less than the actual tolerance range of the scale.

Regards,

posted 02 March 2001 10:51 AM               

I've never had a problem with this with a registrar. I advise clients to avoid the word 'verification' with respect to calibration in any documents and in their 'local language'. It's just not worth a pissing match with an auditor over the definition of the word 'verification' with respect to calibration.

Considering the calibre of quality professionals who make up these forums, and considering how few can articulate the differences with accompanying majority concurrence (as you said, even you are still 'confused' about the differences, it's obvious that the gray area is not going away.

Actually, my perception is anything other than an ajustment is a verification.

For the heck of it, here's the dictionary definition of calibration:

1. to assign, verify, or correct the graduated markings on (a quantitative measuring instrument such as a thermometer).

Here's for verification:

posted 02 March 2001 11:34 AM               

As I understand it:

"Verification" - is
Confirmation by providing "objective evidence" that a specified requirement has been met.

"Confirmation" itself can be any of the following activities.
1) Recalulating tolerances
2) Comparing a new design spec with a
similar one
3) Testing to demonstrate results
(functional or destructive)
4) Reviewing documents before they are used.

posted 02 March 2001 03:02 PM               

2)From our ISO administrator:
- Calibration: Comparisson to a higher
standard within all the
instrument range.
- Verification: Comparisson to a higher
standard in one specific
value.
- Adjustment: Set an instrument back to
acceptable measuring readings
either verification or
calibration need to be
performed after any
adjustment.

As you can see adjusting is different than calibrating.
Marc, on december 26,2000 you posted:
"...calibration is always a documented method of verifying the performance of a
> measuring instrument, usually under controlled conditions, and always by
> comparing it in some way to a specified standard.
It's a comparison to a 'defined' standard - I agree 100%."

and now you say :
Adjustment = Calibration
No Adjustment = Verification.

I think is like Bible, everyone accepts is true but there are different interpretations.

Regards.