Ultrasonic transducer device

An ultrasonic transducer assembly includes a proximal end and an opposing distal end. The transducer assembly includes an outer housing and an electroacoustic signal generating element secured within the outer housing. The signal generating element transmits an ultrasonic signal at a characteristic frequency along an ultrasonic path that is perpendicular to the face of the generating element. An isolation diaphragm is coupled to the proximal end of the outer housing. The isolation diaphragm is thin relative to a characteristic wavelength of the diaphragm material. A fluidic transmission layer is disposed between the electroacoustic signal generating element and the isolation diaphragm. In one embodiment, the isolation diaphragm is at an angle relative to the proximal face of the electroacoustic signal generating element. In another embodiment, a flow meter includes the ultrasonic transducer assembly, and the isolation diaphragm substantially matches the contour of the flow passage within the flow meter body.