No. 99MBB122A
18-44
18.6 Motif-related Parameters
The motif method is a French standard for evaluating surface roughness. This method
was adopted as an ISO standard (ISO12085-1996) in 1996.
Normally, when wave segments are removed from an evaluation profile, the evaluation
profile becomes distorted. This method is designed to remove waviness without causing
distortion.
With this method, an evaluation profile is divided into units called “motifs”, which are based
on the wavelength of a component to be removed, and parameters to evaluate the profile
are calculated from each motif. This section briefly explains how to obtain the motif
parameters.
18.6.1 How to obtain roughness motifs
Use the following procedure to obtain roughness motifs.
1. In order to prevent small bumps from influencing the procedure, obtain the minimum
height (Hmin) used to determine peaks.
Divide the evaluation data into segments that are half the length of the
roughness-motif maximum length, A. For each segment, determine the distance
between the maximum point and the minimum point, and set the minimum height as
5% of the average of these distances.
Minimum height for determining a peak
n
i
hi
n
H
1
1
05.0min
n: Number of measured set lengths
A/2
h
1
h
n
To Next Page
Loading...
