Patent ID: 8234933

Claim:
An ultrasonic meter comprising: an emitter that emits a series of ultrasonic burst signals towards a fluid containing at least one of bubbles and particles, the series of ultrasonic burst signals being reflected by at least one of the bubbles and particles in the fluid to be a series of reflected signals; a receiver that receives the series of reflected signals; and a calculator that calculates a plurality of correlation coefficients by performing a correlation processing on a series of received signals outputted from the receiver, the calculator calculating a physical quantity of the fluid based on the plurality of correlation coefficients, wherein the series of ultrasonic burst signals includes a first, second and third ultrasonic burst part signals, the first ultrasonic burst part signal has a first frequency, the second ultrasonic burst part signal has a second frequency, the third ultrasonic burst part signal has a third frequency, a first time interval is defined between the first and second ultrasonic burst part signals, a second time interval is defined between the second and third ultrasonic burst part signals, the first time interval and the second time interval are different from each other, the series of reflected signals includes a first, second and third reflected part signals, the first ultrasonic burst part signal is reflected by at least one of the bubbles and particles in the fluid to be the first reflected part signal, the second ultrasonic burst part signal reflected by at least one of the bubbles and particles in the fluid to be the second reflected part signal, the third ultrasonic burst part signal is reflected by at least one of the bubbles and particles in the fluid to be the third reflected part signal, the series of received signals includes a first, second and third received part signals, and the plurality of correlation coefficients includes a first correlation coefficient and a second correlation coefficient.