Ultrasonic flowmeter using windowing of received signals

An integrated circuit, comprising:

• a substrate having a semiconductor surface;
• a processor formed on the semiconductor surface;
• a non-volatile memory storing a flow measurement algorithm and instructions;
• a data bus for coupling the non-volatile memory to the processor;
• an address bus for coupling the non-volatile memory to the processor;
• input/output (IO) pins, coupled to the data bus and the address bus for coupling to a first transducer and to a second transducer;
• the processor being operable when executing the instructions to:
• transmit a first pulse train to a first transducer, wherein the first transducer:
• transmits a first ultrasonic wave to a second transducer, the first ultrasonic wave propagating downstream through a fluid in a pipe section in response to receiving the first pulse train, wherein an amplitude of the first ultrasonic wave increases when receiving the first pulse train;
• and
• receives a second ultrasonic wave from the second transducer;
• transmit a second pulse train to the second transducer, wherein the second transducer:
• transmits the second ultrasonic wave to the first transducer, the second ultrasonic wave propagating upstream through the fluid in the pipe section in response to receiving the second pulse train, wherein an amplitude of the second ultrasonic wave increases when receiving the second pulse train;
• and
• receives the first ultrasonic wave from the first transducer;
• generate a first windowed portion of the first received ultrasonic wave and a second windowed portion of the second received ultrasonic wave;
• calculate a signal delay using the first and second windowed portions;
• and
• calculate a flow of the fluid from the calculated signal delay.

An ultrasonic flowmeter, comprising:

• a first transducer and a second transducer positioned on a pipe wall;
• a flow electronics circuit including a transceiver coupled to a processor having an associated memory storing a flow measurement algorithm coupled to the first and second transducers for:
• transmitting a first pulse train to the first transducer, wherein the first transducer:
• transmits a first ultrasonic wave to the second transducer, the first ultrasonic wave propagating downstream through a fluid in a pipe section in response to receiving the first pulse train, wherein an amplitude of the first ultrasonic wave increases when receiving the first pulse train;
• and
• receives a second ultrasonic wave from the second transducer;
• transmitting a second pulse train to the second transducer, wherein the second transducer:
• transmits the second ultrasonic wave to the first transducer, the second ultrasonic wave propagating upstream through the fluid in a pipe section in response to receiving the second pulse train, wherein an amplitude of the second ultrasonic wave increases when receiving the second pulse train;
• and
• receives the first ultrasonic wave from the first transducer;
• generating a first windowed portion of the first received ultrasonic wave and a second windowed portion of the second received ultrasonic wave;
• calculating a signal delay using the first and second windowed portion;
• and
• calculating a flow of the fluid from the calculated signal delay.