It is mainly used to measure the microhardness of various metals and some nonmetallic materials, and can measure the hardness of various parts (machined parts, forgings, cast iron, steel castings, etc.), nonferrous metals, heat-treated parts, etc., and is also suitable for measuring the effective depth of carburizing, quenching hardening layer, coating, surface coating and heat-affected parts of welded parts. It can also be used for observing the internal metallographic structure of various metal parts and collecting, displaying and outputting images. It is especially suitable for measuring the hardness gradient distribution curve of workpiece and measuring the surface hardness of gear after heat treatment, and effectively hardening layer depth.