Autocollimator and tool makers micro scope
Autocollimator The autocollimator is an optical instrument and is used to measure angular displacements with high accuracy of 0.2 seconds arc It can also be used to measure the flatness of a large surface Collimation of light If a point source of light is placed at the focal point of convex lens ,parallel rays of light are reflected by the lens. This is known as collimation of light A device with a lens suitable for causing light rays from a point source to become parallel is known as a collimato r Auto collimation of light Auto collimation of light occurs when reflecting surface is used in conjunction with a collimation lens system The collimation rays will be reflected back from the surface These rays pass through lens ,and unless reflecting surface is perfectly tangential to the lens axis ,will be brought to a focus along side of the light source Principle of the autocollimator From the fig. The light in the form of parallel rays , i...