直読式表面あらさ測定機のH_a指示値に関する一考察

抄録

Three types of high pass filter are used for cut-off in electrical roughness testers employed in Japan. Namely, type a and b in which the cut-off value is assessed at 70 % of maximum transmission in the system, having the straight part of the attenuation curve which the maximum slope of 6 dB per octave and 12 dB per octave, respectively, and type c in which it is assessed at 50 % of maximum transmission in the system, having the straight part of the attenuation curve with the maximum slope of 12 dB per octave.
In this paper, the difference between the value of center line average H_a obtained by roughness testers with the filter of type a and c are discussed in comparison with H_rms values which are obtained from the power spectrum of three samples.
The H_rms (0.75) values of the roughness curve obtained by roughness testers with the filter of type a, type b and type c, which have the same cut-off value of 0.75 mm, are 8595% of H_rms values calculated from the profile curve of the samples.