Interval for Self-Calibrating Measurement Device?

[JoShmo]

It is a gloss meter - I attached a similar model owner manual. But the owner manual does state it is self-calibrating. I want to do the right thing and keep my employer happy and meet the ISO standard at the same time. And Thanks for replying!

Gloss meters, as with similar colormeters and densitometers are simply comparitors which are "set" against a known (usually industry validated) sample. I'd suggest that it's pure verification and NOT calibration (of the truest sense)

 

[Project Man]

I guess I can extend the calibration to next year based on past results (previous years of external calibrations).

You can set the calibration at an appropriate interval. There is nothing magic and or statistical about 365days. Your calibration interval needs to take into account many things (environment, use, manufacturer's recommendations, maintenance, previous calibration results including before and after, etc.)
If you feel confident that you can clearly show an auditor why the appropriate calibration interval is every two years, then set it at two years.

 

[Crusader]

Newer equipment/instrumentation have features/functions that allow for internal adjustment/alignment of the measurement capability. For example, newer analytical balances have internal standard weights that can be used to verify the balance is weighing correctly. However, there are many factors that can affect the accuracy/repeatability of a balance. Too, the internal weights on the balance need to be verified routinely.

Depending on how robust/ accuracy the "self-calibration" routine is on a piece of equipment can extend the calibration frequency/interval. However, for a true calibration of measurement equipment/instrumentation, a known standard with NIST (or equivalent) traceability is needed; and an assessment of uncertainty (or accuracy) ratio.

So if you don't want to pay an outside vendor to perform the verification, you should consider acquiring the standard yourself and determining what interval that standard should be re-verified. Also, you should have a procedure/work instruction written to address the needs.

This gloss meter has a standard included with it and it was certified by a NIST lab. We've been sending out this meter/std every year. Until now, a new guy thinks that we are wasting money and he read that this gauge self calibrates...so he thinks we are okay.

 

[Crusader]

You can set the calibration at an appropriate interval. There is nothing magic and or statistical about 365days. Your calibration interval needs to take into account many things (environment, use, manufacturer's recommendations, maintenance, previous calibration results including before and after, etc.)
If you feel confident that you can clearly show an auditor why the appropriate calibration interval is every two years, then set it at two years.

Yup. I have concurrence that the meter is a reference check and does not accept or reject as was once indicated to me. I can change this whole thing now to a verification process and calibrate when we feel like it. I don't like it, because all along the meter readings were important and now all of a sudden the readings are not as important. Hmmmmm.

 

[howste]

...a new guy thinks that we are wasting money...

Does he know how much a reject will cost when the gloss is off on a production run of parts?

 

[Crusader]

Does he know how much a reject will cost when the gloss is off on a production run of parts?

I hear ya. But, I am being instructed on what to do from the top. I have an agreement amongst the ranks to have the Standard checked annually. And to purchase an extra Standard.