The design of a portable surface roughness measuring instrument is presented.This instrument is composed of single chip computer as the kernel.The functions of surface roughness automatic measuring

display and communication are implemented by using the technologies of piezoelectric sensor

liquid crystal display and RS—232 communication

etc.The result shows that the instrument has the characteristics of broad measuring range

high-precision

simple structure and low-power.It can be used in measurement room

laboratory

and production workshop for the surface roughness measurement of planner

cylindrical

inner hole

and groove

etc.It has been successfully used in engineer testing and solved the needs of the actual production.