The application of Atomic Force Microscope for roughness measurement

Atomic Force Microscopes (AFMs) are capable of measuring surface roughness on the nanometer scale. In this paper, we describe a preliminary study of testing the surface roughness of standard gauge blocks by AFM. According to Japanese Industrial Standard (JIS B 7506, 1987), the roughness of the measuring face shall not exceed 0.06 mum Rmax. for Grades 00 and 0, and the roughness seems to be a significant surface parameter for gauge block on uncertainty evaluations. We use a PTW Grade 00 gauge block in this study and take five images of scan size of 60 mum 60 mum by AFM, and than grab five line profiles from each image. The average values of Ry(Rmax) for these 25 line profiles and that of Sy for these five 3D images calculated by commercial software (Scanning Probe Image Processor, SPIP) are 22.09 nm and 69.14 run respectively, and the corresponding standard deviations are 2.93 nm and 10.35 nm respectively. Up to present, there are no other international standard documents describing 3D roughness. It would be meaningful that if the AFM is compatible with traditional stylus instruments in measuring roughness.