Abstract: Ultrasonic transducers for use in time-of-flight flow measurement are made by clamping a conformal material between a face of a piezoelectric element and a housing so as to efficiently acoustically couple the piezoelectric element to a flowing fluid wetting the housing. Both in-line and probe sensing heads are described, where the in-line sensor heads make use of side-looking transducers. Acoustic isolation arrangements are used to ensure that the transducer transmits and receives acoustic energy in a single, well-defined direction. Various pre-loading arrangements, such as metal springs that can be set by driving a wedge between the spring and the housing, are used to controllably force the piezoelectric element toward the housing.

Abstract: A significant problem in the flow probe art is that of accurately positioning a flow-sensing portion of the probe at a selected location within a pipe. Several arrangements are provided for determining the insertion depth of flow sensing probes, for measuring diameters of the pipes in which they are inserted, and for detecting the depth of those pipes. These generally involve adding to the flow probe a depth measurement device for generating an energetic beam that is reflected from the pipe or from an insertion fitting. One such sensor uses a phased array of piezoelectric element to serve both in a pulse-echo distance measurement device and in a time-of-flight flow measurement device.