| 摘要 |
According to Figure 2, an echo sounding device comprising digitisation of the measurement results is provided, in addition to the usual modules for an echo sounding system, with a receiving amplifier which automatically sets itself to the amplitude of the most distinguished echo, with an analog evaluation circuit which converts the echo transit times into voltage pulses by picking up sawtooth voltages and stores them as mean value of the preceding sounds, and with window electronics which are controlled by the mean voltage value and thus by the mean water depth of the last soundings. The window electronics have the effect that only echoes which fall into the window with a certain width can have an influence on the control of the amplifier, the averaging and the gate stage for starting and stopping the counter for the digitisation. As a result, the system of controls is fixed to the ground echo and cannot be disturbed by pre-echoes. By gating the stop pulses into the echogram as a distinct black front edge of the relevant echoes, the digitisation processes of the echo sounds are monitored, on the one hand, and, on the other hand, the output values are documented for the EDP. <IMAGE>
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