Abstract: A circuit arrangement for separating high-frequency pulses produced successively in time at a piezoelectric transducer of an acoustic reflection lens arrangement. According to the invention, the transducer is preceded by a three-way pin switch, the common end of the wiper of which is connected to the acoustic lens, the other end of the wiper being alternately connected in a first position to the output of a transducer oscillator, in a second position to a 50-Ohm resistor, or in a third position to a measurement circuit.

Abstract: Method and apparatus for detecting the distance between an ultrasonic objective and an object to be imaged in order to prevent contact between the two. For this purpose, light rays, after entering into an immersion means (water) between the objective and the object, being reflected by the object, and emanating from the immersion means are fed through the ultrasonic objective to a photo-receiver and converted into electric signals. The front face of the lens body of the ultrasonic objective is provided with an opaque ring zone. This arrangement makes it possible simultaneously to illuminate the object.

Abstract: A spherically concave frontal surface of an acoustic lens in an acoustic microscope is cleaned and wetted by directing a stream of a cleaning and wetting liquid, slightly larger in diameter than the concave surface, against the concave frontal surface of the lens.