| 摘要 |
PCT No. PCT/DE94/00670 Sec. 371 Date Dec. 18, 1995 Sec. 102(e) Date Dec. 18, 1995 PCT Filed Jun. 15, 1994 PCT Pub. No. WO95/00862 PCT Pub. Date Jan. 5, 1995The method makes it possible, in particular, to measure distances which lie within the ambiguity zone of the ultrasonic transmission/reception unit. The ultrasonic transmission/reception unit comprises a single ultrasonic transducer which is operated in pulse-echo mode. The time te1 of the first received echo is initially determined. If this time lies outside the double dead time 2tT, then the measurement is unambiguous and the propagation time of the sound, which is proportional to the difference between the ultrasonic transmission/reception unit and the object, is output. Otherwise, the propagation time of the sound is determined from the difference between the arrival times of two successive multiple echoes from the same object.
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