Q. What is the working principle of a surface roughness tester?

Answer

The surface roughness tester is an instrument used for measuring the surface roughness of a particular workpiece. The surface roughness cannot be determined by the naked eye as the irregularities are very small sometimes. For this a surface roughness tester is used which consists of a small stylus and this is used to draw at a constant speed across the workpiece’s surface for a specific distance. With this an electrical signal is produced. Further the signal is amplified in order to obtain a higher magnification. The tester’s stylus tip is equipped with a detector tip which helps in tracing the surface of the sample. This then electrically detects the stylus’ vertical motion.