Dimensional Measurement Uncertainity - Inspection of a component

[haripachan]

Hi,

I have to write a procedure for dimensional inspection of a component. This component has 10 dimensions and measurement involves a combination of conventional instruments and coordinate measuring machine.

I have been asked to mention about measurement uncertainity at this stage, where I am unable to find ways.

Kindly help,...

 

[BradM]

Re: Dimensional measurement uncertainity

Hi,

I have to write a procedure for dimensional inspection of a component. This component has 10 dimensions and measurement involves a combination of conventional instruments and coordinate measuring machine.

I have been asked to mention about measurement uncertainty at this stage, where I am unable to find ways.

Kindly help,...

Hello there! Thanks for dropping by the Cove.

I have a few basic questions. Have you ever calculated uncertainty before? Or have you done a few, and are wondering how to approach dimensional uncertainty?

Guidlines for evaluating and expressing uncertainty


The root thread for the above that has some pretty good stuff in it:

17025 Accreditation Audit - Test Laboratory

Here is another pretty good thread that may be of interest to you (long but good):

Types of Measurement Uncertainty of Different Devices - Is there any Standard?

Finally, this one has a dimensional uncertainty analysis that will be of interest:

Measurement Uncertainty.pdf

Hope this helps.

 

[haripachan]

Re: Dimensional measurement uncertainity

THANK YOU,

WELL I AM DOING SUCH AN ANALYSIS FOR THE FIRST TIME...WHATEVER I HAVE DONE COUPLE OF EXERCISES FOR MICROMETER...

BUT I NEED TO KNOW, HOW TO INCORPORATE UNCERTAINITY OF MEASUREMENTS IN PROCEDURE...

rEGARDS

 

[Hershal]

Re: Dimensional measurement uncertainity

First thing to do: Get training in uncertainty. Go to www.ilac.org and search for an accrediting body near you, get in touch, and see if they know of courses offered locally to you.

If not, then distance learning may be the option.

www.wptraining.com

www.quametec.com

Afterward take the information and include basic concepts in the production check procedure. Don't make that procedure too complicated, just a decent discussion for production folks to say that uncertainty means errors , here are some that affect them, and things they can do reduce the error.

Hope this helps.

 

[bobdoering]

Re: Dimensional measurement uncertainity

Don't make that procedure too complicated, just a decent discussion for production folks to say that uncertainty means errors , here are some that affect them, and things they can do reduce the error.

This is a good suggestion. It is hard enough for the quality professionals to grasp uncertainty, don't expect it to impress they layman much.

 

[True Position]

When I was tasked with this same issue the linked guide was a huge help to me: http://www.a2la.org/guidance/est_mu_dimen.pdf

It is written in a very readable style showing what go's into uncertainty calculations and gives some well explained examples. Sadly it mostly focuses on calibration but there is information on testing as well.