Patent ID: 8402840

Claim:
A device for sensing fluid flow within a pipe, which pipe has a pipe wall, comprising: a sensor housing having at least one pressure vessel enclosure and hardware for mounting the enclosure on an exterior surface of the pipe wall, which enclosure includes a base, side walls, and a cap, wherein the base has a pipe-side surface that mates with the exterior surface of the pipe wall, and wherein the base and the pipe wall have substantially similar resonant frequencies and acoustic impedance, which sensor housing is adapted to be attached to the pipe wall such that the pipe-side surface of the base is mated with the exterior surface of the pipe wall; and a fluid flow meter having plurality of ultrasonic sensors disposed within the at least one pressure vessel enclosure, each sensor having a transmitter and a receiver, wherein the transmitters are adapted to transmit signals at one or more frequencies including frequencies that are substantially equal to the resonant frequencies of the base and pipe wall.