Temperature (O-inspect 543)

[[Cl...]]

We have two parts approx. 6.0" long. One is .0934 in diameter, the other is .1247, made form both M2 and 440a SS. There is a "Master part" for each diameter. These are ran daily through the program to ensure that the measurements are consistent. Yesterday when they were run for validation, one dimension in particular (measured with the CFS) measured .1968", while the same part measured today was .1974". The temperature is fluctuating 3-4 degrees (73 - 76/77). I re-qualified all the sensors (tactile/camera/CFS) and nothing has changed in the programs. Stylus are clean and solid. Can a 3-4 degree temperature increase affect enough change in the material to see a .0006 difference?

[[Am...]]

It depends on the material I don't think 440 SS would change that much with such a small diameter. I have a o-Inspect 322 and I know with that model the factory spec on the accuracy is 2.4 + L/150mm which drops to 2.6 + L/150mm in a temp over 24°C so at 77°F you are possibly getting worse accuracy but only slightly (and not necessarily but they are allowed a bigger range at that temp). What kind of stylus are you using?

[[An...]]

we also had a 543 once, which we gave back after 6 months.
It is so that the 543 with high temperature differences does not come clear.
This CMM takes that very badly.

[[Cl...]]

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The features that are changing are measured with the white light sensor.

[[Ja...]]

Temperature is not an issue for this problem. The thermal coefficient of expansion for 440 stainless is 0.00000567"/inch/degree. For a 0.197" diameter:

0.00000567 x 0.197 = 0.00000112 per degree
0.00000112 x 4 degrees = 0.00000448