Patent ID: 8181536

Claim:
An ultrasonic transducer for a pipe comprising: an ultrasonic source which produces plane waves in a fluid flow; and a housing having a face at least a portion of which is curved through which the plane waves produced from the source disposed in the housing are emitted and directed outward towards the pipe's interior wall so a full cross-section of the fluid flow in the pipe's interior can be measured, wherein a desired angle, φ desired, of the conical shape is defined by: ∅ Desired = tan - 1 ⁡ [ D 2 - r 2 L 2 + sin ⁢ ⁢ ∅ face · r z ] where D is the diameter of the pipe, L is the length of the pipe, r is the radius of the transducer, sin ⁢ ⁢ ∅ face C window = sin ⁢ ⁢ ∅ refract C fluid ∅ Desired = ∅ face - ∅ refract .