Measuring fine tubing (< 0.100") "Wall by weight"

[Dano]

Does anyone have any experience/technical knowledge for measuring fine tubing (< 0.100") "Wall by weight"?

 

[Ninja]

No experience here...and cannot easily find the term "wall by weight" described anywhere...do you have a link to share regarding this technique?

 

[Dano]

Thanks. A link to something is what I am looking for. The method is basically measure the length of the tube, the tube OD, and the weight of the length. Then using these and the known density of the material the wall (and ID) can be calculated. I was hoping to find an ASTM or ANSI or even a paper on the method. Not having any luck.

 

[Jim Wynne]

Thanks. A link to something is what I am looking for. The method is basically measure the length of the tube, the tube OD, and the weight of the length. Then using these and the known density of the material the wall (and ID) can be calculated. I was hoping to find an ASTM or ANSI or even a paper on the method. Not having any luck.

Measure the ID and the OD. Subtract the former from the latter and divide by two.

 

[Eredhel]

What are you actually trying to measure? Is it some kind of gun drill type hole? Do you need an ultrasonic tester?

 

[Dano]

The tube is a precious metal alloy ~ 0.023" OD by 6' in length. The wall is spec is 0.001" +/- 0.00025" Ultrasonic hasn't been helpful, it can't distinguish between the ID and OD at this thickness.

 

[Eredhel]

That's a tough one. I'll shoot you a PM real quick.

 

[Ninja]

If I were a customer buying this...to the spec stated...I wouldn't accept a weight measurement. It gives total material, but not uniformity.

If you are extruding it, you can make a good case for measuring end cuts (destructive sampling off each end, measuring cross section) on a CMM.

 

[Eredhel]

A destructive test that proves out the process is a good idea, hadn't thought of that. Edit: And of course could be done at a sample too.

 

[Dano]

Oddly, it is on the customer specification, but they don't actually do it. They are dependent on supplier resources, confirming by the C of C