| 摘要 |
The present invention relates to an ultrasonic flow sensor equipped with at least one ultrasonic transducer (A, B) for transmitting and receiving ultrasonic signals (A 0 , B 0 ) and one receiver unit ( 4 ) that is connected to the ultrasonic transducer (A, B) and detects a zero crossing (N) of the ultrasonic signal (A 0 , B 0 ) as a reception time after the ultrasonic signal (A 0 , B 0 ) has exceeded a predetermined threshold (SW). The measurement precision of the sensor can be significantly improved if the receiver unit ( 4 ) determines the time of a value characteristic of the ultrasonic signal (A 0 , B 0 ) and determines the relative time shift (deltat) of the characteristic value (Amp<SUB>max</SUB>, T<SUB>s</SUB>) in relation to the zero crossing (N<SUB>0</SUB>, N<SUB>1</SUB>) that is detected as the reception time (t<SUB>0</SUB>).
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