INTERFERENCE METHOD MEASURING GEOMETRIC CHARACTERISTICS OF OBJECT AND DEVICE FOR ITS REALIZATION Russian patent published in 2003 - IPC

FIELD: measurement technology. SUBSTANCE: interferometer employed in correspondence with proposed method uses surface of tested object as one of mirrors. Interferometer is illuminated by bean of monochromatic radiation on two wave lengths, photoelectric conversion of brightness of sum of two interference pictures to electric signal is conducted. Signal of carrier frequency and signal of envelope are extracted from obtained signal and amplitudes of these signals are measured and used to make judgment on measured value. Interference device to measure geometric characteristics of object includes source of monochromatic radiation emitting on two wave lengths simultaneously, interferometer, photoelectric brightness converter of sum of two interference pictures to electric signal. Device is equipped with subtracter of constant component of signal, amplitude detector, comparator, band-pass filter and two units of phase locking. EFFECT: enhanced measurement accuracy, noise immunity, speed with maintenance of expanded range of unambiguity of measurements. 2 cl, 3 dwg