Hello everybody
At first i would like to thank you all for this great forum.

We have Talyrond 73 roundness instrument in our lab. and I have to calculate measurement uncertainty for roundness until next Wednesday.
My problem is that, i couldn't arrange the uncertainty budget because i have no idea about which parameters affect the result.
All the helps are welcome.

Haldun

First, begin with your Type A. This is the readings that you take. Get standard deviation, divide that by square root of n, where: n=the number of readings you take.

Next, take the uncertainty of your machine's clibration. This is a Type B and is normal distribution.

Then environmentl issues, these are Type B and are rectangular, so divide by square root 3.

There may be other issues also, but this will get you statred.

Hershal

Thank you so much for your help Hershal.

I saw an example of roundness uncertainty budget in the following NIST pubblication: emtoolbox.nist.gov/Publications/NISTJResNov-Dec97-102-6.pdf .
I hope it helps you.

Sermet