发明名称 |
Sonic or ultrasonic distance measuring device |
摘要 |
The sonic or ultrasonic distance measuring device used for example to measure the filling level in a container comprises an electroacoustic transducer which operates alternately as transmission transducer for the transmission of sonic or ultrasonic pulses and as reception transducer for the reception of the reflected echo pulses. Connected to the transducer is a signal processing circuit which includes an amplifier with controllable gain and a threshold value discriminator. A gain control circuit controls the gain of the amplifier during a predetermined period after the start of each transmission pulse in accordance with a stored function which is fixed in accordance with the dying-down behaviour of the transducer so that the electrical signals originating from the dying-down of the transducer after amplification are smaller than the threshold value of the threshold value discriminator but are as close as possible to said threshold value. As a result the evaluation of echo pulses which occur during the dying-down of the transducer is possible.
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申请公布号 |
US4675854(A) |
申请公布日期 |
1987.06.23 |
申请号 |
US19840656229 |
申请日期 |
1984.10.01 |
申请人 |
ENDRESS U. HAUSER GMBH U. CO. |
发明人 |
LAU, JUERGEN |
分类号 |
G01F23/292;G01F23/28;G01F23/296;G01S7/529;G01S15/10;(IPC1-7):G01S9/68 |
主分类号 |
G01F23/292 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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