Abstract: A method and an apparatus for dial indicator calibration comparing the real displacement of the dial indicator rod with its ideal linear displacement during each calibration interval given by the dial indicator hand, having a Michelson interferometer with a laser as a linear displacement transducer, an opto-electronic transducer to read the dial, indicator hand position for each calibration interval, an electronic control urgent which controls the operation of the whole apparatus and feeds to a printer the measuring errors in length units and the corresponding calibration intervals.