In today's world of high-technology products, the most important requirements of dimensional and other accuracy controls are becoming very stringent as a very important aspect in achieving quality and reliability in the service of any product in dimensional control. Unless the manufactured parts are accurately measured, assurance of quality cannot be given. In this context, the course deals with the basic principles of dimensional measuring instruments and precision measurement techniques. The course begins with the basic concepts of metrology and measurement standards. Then, linear, angular, geometrical shape metrology along with interferometry techniques and various types of comparators are explained in the subsequent modules. Concepts of limits, fits and tolerances and surface finish measurement, screw thread and gear measurements are also presented in detail. Finally, the course deals with metrology of machine tools and advanced metrology respectively. (from nptel.ac.in)