Single-body dual-chip orthogonal sensing transit-time flow device using a parabolic reflecting surface

An ultrasonic sensor system, comprising:

• a duct for providing a flow path for a fluid in a flow direction;
• an ultrasonic flow sensor sealingly coupled to the duct, including:
• a first transducer to transmit a signal,
• a second transducer to receive the signal,
• at least one end cap to enclose and isolate the first transducer and the second transducer from the fluid;
• and
• a curved reflecting surface to reflect the signal toward a reflective surface located on the end cap, wherein the reflective surface lies along an axis approximately half-way between the first transducer and the second transducer, a path of the signal extends generally along a longitudinal axis of the duct parallel to the flow direction, the path extends from the first transducer to the curved reflecting surface to the reflective surface to the curved reflecting surface to the second transducer.

A method of determining a flow rate of a fluid in a duct, comprising:

• transmitting a signal from a first transducer through an end cap and a fluid, wherein a path of the signal extends generally along a longitudinal axis of the duct parallel to a direction of fluid flow, and the end cap encloses the first transducer and a second transducer and acts as a barrier to the fluid;
• reflecting the signal from a curved reflecting surface;
• receiving the signal at the second transducer;
• measuring a first time between transmitting the signal in a forward direction and receiving the signal;
• measuring a second time between transmitting the signal from the second transducer in a reverse direction and receiving the signal at the first transducer;
• and
• comparing the first time to the second time to determine the flow rate of the fluid.