Does a gage used for a visual verification need to be calibrated?

[QualityKRSC]

Does a gage used for a visual verification need to be calibrated?

Our customer wants " typically 10 strands of braiding material" within a 25mm area.
We have a block with a 25mm window cut into it for this visual check.

This visual gage will never see wear or deterioration in our production environment as it is only to be laid over the braid material and used as a window.

Thoughts please. Thank you,
Jean

 

[XRNPO]

As a Quality Auditor with over 20yrs of experience I would require that any gages in the Control Plan be individually identified, within a gage tracking system and calibrated. Your working environment does sound comfortable, but would an inexperienced associate be able to note dropped or any other damage that may influence the gage? The method and frequency of calibration would be more discussable.

 

[Sidney Vianna]

Thoughts please

That is not a gage. That is a fixture. Irrespective of that, verify it initially and then set the next verification date 10 years later. That product line will be gone by then and that fixture will not exist anymore. Voilà, problem solved.

 

[QualityKRSC]

I see your point. I will make the addition to our calibration system of these check gages.
Thank you for the response.

 

[QualityKRSC]

That is not a gage. That is a fixture. Irrespective of that, verify it initially and then set the next verification date 10 years later. That product line will be gone by then and that fixture will not exist anymore. Voilà, problem solved.

Thanks Sidney,
The frequency will be out years.

 

[Bev D]

Sidney is correct that the thing is a fixture and not a gauge as it doesn’t measure anything.
However, I would add that IF the number of threads is a critical characteristic, then you might want- or need - to perform a study on the ability to count the number of threads repeatably and ‘accurately’. Typically humans can count 1-5 items fairly well. Over that it becomes more and more difficult. Something to consider…

As a fixture it doesn’t require ‘calibration’ but it does require a verification of size and like other fixtures if there is any noticeable damage one woudl wan tot verify the size OR replace the fixture….otherwise Sidney’s advice regarding timing is spot on.

 

[Ed Panek]

I agree with Bev. What did your risk analysis determine? This is critical and undetectable later in production? This is detectable in production and used as an efficiency boost??

 

[Scanton]

A plug gauge (or pin gauge) doesn't measure anything, however it is still considered a gauge, "an attribute gauge".

There must be a limit to the size of the window, or it would not function as a gauge (fixture) for its desired purpose.

Can you set limits on the size of the window and measure at set intervals (even it if is 10 years)?

Also some sort of attribute R&R would probably be a good idea so you can show it is fit for purpose.