| 摘要 |
<p>The invention concerns a method for measuring the propagation time Tp of a signal, in particular an ultrasonic signal between two transducers consisting of a transmitter and a receiver at some distance from each other. The transmitting transducer is subjected to an excitation signal comprising n successive pulses of period Te resulting in the transmission of an ultrasonic wave in the direction of the receiving transducer. The ultrasonic wave generates a reception signal in output of the receiving transducer. An intermediate propagation time Tint is started as from the start of the excitation of the transmitting transducer. The reception signal in output of the receiving transducer is detected and the oscillations of said reception signal are counted. The measurement of the intermediate propagation time Tint is stopped when the i-ith oscillation is detected. The propagation time T¿p? of the signal is determined by forming the difference Tint - i x Te. Advantageously, the measurement of the intermediate propagation time Tint is stopped for the i-i?th¿ oscillation of the reception signal corresponding to a maximum amplitude of the reception signal.</p> |
