Dimitar Iankov
2014-03-24 14:56:00 UTC
Hi all,
I was comparing the output for surface roughness from different analysis tools. Very often they separate waviness from roughness by default and only then calculate the roughness parameter (Rq, for example). Gwyddion also do this in the "Roughness" tool but only for a profile (1D) and uses a ratio of the cut-off frequency as user input. Other programs use the wavelength (lambda_c) of the waviness as input. I think this is because in ISO 4287 one has to choose lambda_c to be approx. 1/5 of the scan length. Of course, both values are connected to each other, however the precision in the cut-off input field in Gwyddion (2 decimal places) seems to me a little bit too low.
My question is, how to do waviness separation in 2D (i.e. Sq after ISO 25178)? The "statistical quantities" tool doesn't have this option. This seems to be a common step in other programs and that's why the results often deviate from Gwyddion.
Thanks!
I was comparing the output for surface roughness from different analysis tools. Very often they separate waviness from roughness by default and only then calculate the roughness parameter (Rq, for example). Gwyddion also do this in the "Roughness" tool but only for a profile (1D) and uses a ratio of the cut-off frequency as user input. Other programs use the wavelength (lambda_c) of the waviness as input. I think this is because in ISO 4287 one has to choose lambda_c to be approx. 1/5 of the scan length. Of course, both values are connected to each other, however the precision in the cut-off input field in Gwyddion (2 decimal places) seems to me a little bit too low.
My question is, how to do waviness separation in 2D (i.e. Sq after ISO 25178)? The "statistical quantities" tool doesn't have this option. This seems to be a common step in other programs and that's why the results often deviate from Gwyddion.
Thanks!