Sensor apparatus

摘要

A sensor apparatus (180) is provided for measuring characteristics of a wall of a structure (100) and/or a medium in contact with the structure (100), wherein the sensor apparatus (180) includes a transducer arrangement (200, 300, 510, 540) disposed at least partially around a planar or curved surface of a wall of the structure (100), or disposed over a region of a planar or curved surface of a wall of the structure (100). The sensor apparatus (180) includes a transducer waveguide including at least one free distal end whereat one or more driver and/or receiver elements are mounted on one or more sides of the at least one free distal end. Moreover, the transducer arrangement (200, 300, 510, 540) is operable, when interrogating the structure (100) to perform at least one of: switching between selected acoustic wave modes present in an acoustic wave propagation, steering an acoustic propagation direction of the acoustic wave propagation. The one or more driver elements are operable to excite the acoustic wave propagation within the wall of the structure (100) for providing information indicative of properties of the wall and/or material present in a vicinity of the wall which interacts with the acoustic wave propagation. The wall (100) pertains, for example, to a pipe, a conduit, a vessel, a chamber, a planar sheet, but is not limited thereto.