Abstract: An improved method and apparatus for inspecting the curved surface of a stationary article includes a mirror which is moved to direct a beam of light from a light source through a lens against each point of an arcuate series of points on a curved surface of the article. A second lens focuses beams of light reflected from the article onto a linear detector. The distance between locations at which the reflected light beams are focused on the linear detector corresponds to the distance at which points on the surface of the article are offset due to the curvature of the surface of the article.

Abstract: A first array (A) of ultrasonic transducers transmits ultrasonic shear waves circumferentially around an examined cylindrical object (110). A second array (B) transmits ultrasonic shear waves axially along the examined object. Triggering pulses from a triggering amplifier (22) are switched by a multiplexer (24) to each individual transducer of the first and second arrays. As one of the transducers assumes the role of a transmitting transducer and transmits an ultrasonic wave, the other transducers of the first and second arrays assume a receiving mode to receive reflected ultrasonic components. A wave travel timer (26) measures the duration for an ultrasonic wave to be transmitted from the transmitting transducer to a defect and for a reflected component to propagate from the defect to the receiving transducer.