Optical parallel (OP) is made of transparent glass with a parallel and flat measurement surface, it is used to measure flatness and parallelism by means of light wave interference. The Mitutoyo optical parallel (OP) is mainly used to measure flatness and parallelism on the measurement surfaces of the micrometer.
Optical flat (OF) is made of transparent glass with a very flat measurement surface and is used for flat wave interference. It is often used to check the measuring faces of gauge blocks.
Click here for the flatness and parallelism evaluation method using optical parallel (OP) and optical flat (OF).
Click here for optical parallel (OP) and optical flat (OF) on sale at Mitutoyo