International Research Journal of Education and Technology

The profilometers available in the industries are of different techniques. But most of them use a pointed crystal stylus which rubs on the specimen for a small linear dimension. The various surface topographical factors like waviness, texture, lay, manufacturing pattern, clusters of metallurgical phases etc. are spread throughout the surface which are random and therefore only surface   roughness value for a local gauge length is not suitable for surface contact of mechanical engineering / tribological components. This has been observed by many researchers in the field.

The contacting and non-contacting type of techniques used for the measurement of surface roughness is very expensive even when the measurement comes to a flat component and those of spherical surface is even more expensive. With each technique there is a surface parameter that is associated. This parameter associated is to be interpreted to come to a result that can be accepted and compared with the other results.

The contacting type instruments involve movement of stylus over the specimen who can scratch the specimen surface and the tip of the stylus also deteriorates. With contacting type of instruments, the hardness of the material of the two coming in contact is also a point to be considered as the more hard material would try to change the geometry of the other material.