Abstract: Method and device for determining the position of a piston in a cylinder comprising use of both ultrasound transducer and magnetometer for transmitting and receiving signals that are interpreted in a signal processor for determining the position of the piston.

Abstract: Apparatus for condition control of a pipeline with a fluid flow pipe for transport of a fluid, comprising a plurality of ultrasonic transducers arranged in the vicinity of the external surface of the pipeline. By emitting, receiving and analyzing ultrasonic signals by means of ultrasonic transducers it is possible to perform a characterization of the pipeline, for example a measurement of the pipeline wall thickness. Ultrasonic transducers are arranged as an integral part of at least one tape.

Abstract: The invention relates to a method and a device for determining the thickness and topography of buoyant objects, especially ship's hulls (1), by means of a beam (2, 17) carrying an array of ultrasound sensors (3). The object (1) and the beam (2) are moved relative to each other in the object's longitudinal direction while the distance between the object and the beam are automatically adjusted by raising/lowering the beam (2) by means of lifting means (6) and/or distance elements secured by floating bodies (4). The invention also relates to a device for implementing the method.