Patent ID: 8744785

Claim:
An ultrasonic flow sensor, comprising at least one ultrasonic transducer for transmitting and receiving ultrasonic signals, and a receiver unit ( 4 ) connected to the at least one ultrasonic transducer that detects a predetermined event (N) of an ultrasonic signal as a reception time (t 0 ), wherein the receiver unit ( 4 ) determines a time (t 1 ) of a characteristic value of the ultrasonic signal as well as a time shift (Δt) of the time (t 1 ) relative to the reception time (t 0 ) and uses the time shift (Δt) to determine a correct time value for the reception time (t 0 ), wherein the receiver unit ( 4 ) determines a chronological position (T s ) of a focal point of either the ultrasonic signal or its envelope curve ( 6 ) as the characteristic value, wherein Ts ~ ( ∑ K = 1 n ⁢ K * A ⁡ ( K ) ) / ∑ K = 1 n ⁢ A ⁡ ( K ) .