| 摘要 |
In a method and a circuit arrangement for processing received pulse signals in acoustic, electronic and/or optical instruments, acoustic or electromagnetic pulses are sent at time intervals through a measuring system containing a flowing medium. From the transit time of the pulses, a particular characteristic of the medium which depends on the sound or wave velocity is inferred. To achieve a very significant reduction in the influence of the large fast fluctuations of the transfer factor on the position of the front edge of the received pulse signal in time, the instantaneous value of the received signal is compared at any instant with the instantaneous value of the same received signal received earlier by a fixed time difference. The output signal is supplied when the ratio of the two signals exceeds a predetermined amount. <IMAGE>
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