发明授权
- 专利标题: Arrangement for detecting spatial inhomogeneities in a dielectric
- 专利标题(中): 用于检测电介质中的空间不均匀性的装置
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申请号: US765726申请日: 1985-08-15
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公开(公告)号: US4752727A公开(公告)日: 1988-06-21
- 发明人: Georg Schneider
- 申请人: Georg Schneider
- 申请人地址: DEX
- 专利权人: Endress u. Hauser GmbH u. Co.
- 当前专利权人: Endress u. Hauser GmbH u. Co.
- 当前专利权人地址: DEX
- 优先权: DEX3433148 19840910
- 主分类号: G01N27/22
- IPC分类号: G01N27/22 ; G01F1/712 ; G01P5/18 ; G01P5/00
摘要:
The arrangement includes a capacitive probe comprising pairs of sensor electrodes, arranged in a pseudo-random sequence, with which a common transmitting electrode is associated. The transmitting electrode is fed by an electrical voltage source and to the sensor electrodes of each pair an electrode circuit is connected which generates an output signal which corresponds to the difference of the displacement currents induced in the sensor electrodes. The electronic circuit is constructed such that it maintains the sensor electrodes at any time at a virtual ground potential. For this purpose each sensor electrode may be connected to the inverting input of an operational amplifier whose non-inverting input lies at the potential at which the sensor electrodes are to be held with respect to the supply voltage. The sensed signal is used in a correlative measurement of speed or travel time.
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