Curve filter

[[Cl...]]

I vaguely remember a post about how to calculate the wavelength for filtering a curve. Seems it was curve length x 7.

Is this correct? I have a 2d curve. Using it to evaluate line profile. I also am not clear if it is Gauss or Spline?

[[Ma...]]

Gauss for closed loop, Spline for open curves.

I think that that calculation can be in manuals. -> I found that Lc should not exceed half of length of curve.

[[No...]]

I don't understand how the curve length influences the cut-off wavelength.

Purpose of filtering would be to eliminate roughness and waviness from the scanned profile. The only thing that influences the cut-off wavelength (to me) would be the probe diameter.

The same principle applies to planes, lines and circles.

Look at the appropriate standard for the right filter settings. Or in the Zeiss Cookbook.

 

P.S. The "curve length x 7" is probably the point distance x 7. I guess software needs to have a minimum amount of point so identify a wave. With 0.05 mm point distance, the minimum cut-off would be 0.35 mm. But you don't have to bother to calculate this yourself: standards for filter settings also dictate the minmum point distance.

[[Je...]]

Relevant article about form and filtering:

https://cmm-quarterly.squarespace.com/articles/form-measurement-back-to-basics

[[Cl...]]

Thank you, gentlemen.