Abstract: In the ultrasonic inspection of test pieces, particularly tubular materials, a device for coupling a transducer to the surface of the test material, by a liquid medium, incorporates desirable features of both "contact" and "immersion" transducers. Disclosed is a coupler the housing of which has a cavity having a water supply inlet and an air exhaust vent. Water flow into the cavity if so controlled as to initially purge air from the cavity to fill it with water, after which the water flow is at a carefully controlled rate effective to keep the cavity filled while supplying fresh water only to the extent necessary to make up for water leaking out through a narrow gap defined between the test piece and the face plate of the disclosed coupler. The water within the cavity provides a liquid couplant between the test piece and a transducer carried by a holder mounted in the cavity for precision adjustment.

Abstract: An electrical system is disclosed, in which a conventional detector device produces a signal upon its sensing a characteristic or property of a conveyed object at a location upstream, on a conveyor system, from a control location at which the object is to be marked, sorted, segregated, removed, or otherwise acted upon because of said property having been detected. The signal is fed as input to an integrated circuit shift register, in binary form. The shift register is "clocked" by a signal derived either from the power line or other fixed frequency source or from a rotary pulse generator that senses the speed of the conveyor. The register output is connected to a relay amplifier circuit by means of which the original input signal, delayed by the time required to "clock" it through the shift register, is fed to an external sorting, marking or control device disposed at the mentioned, downstream control location.