Fluid dielectric constant sensing device and method employing the same
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsKatsuaki Yasui, Mitsuhiro Ono, Susumu Nagano
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Abstract
A dielectric constant sensing device of the present invention comprises a transmission line consisting of a first electrode formed of a conductor being wound like a longitudinal cylinder, a second electrode provided to be separated from the cylindrical surface of the first electrode at a predetermined distance, and a chamber for introducing a measured fluid between the first electrode and the second electrode, whereby a dielectric constant of the measured fluid can be sensed based on a rate of a pulse voltage wave propagated over the transmission line. Accordingly, the fluid dielectric constant sensing device which is able to attain high precision by a simple structure can be provided.
Claims20
A fluid dielectric constant sensing device comprising:
- a first electrode formed of a conductor being wound like a longitudinal cylinder;
- a second electrode separated from the cylindrical surface of the first electrode at a predetermined distance;
- an introducing portion for introducing a measured fluid between the first electrode and the second electrode;
- a pulse signal generating means for applying a pulse signal to a transmission line which includes the first electrode, the second electrode, and the introducing portion;
- a pulse signal sensing means for sensing the pulse signal after the pulse signal has propagated over the transmission line;
- and
- a dielectric constant sensing means for sensing a dielectric constant of the measured fluid based on a period of time from generation of the pulse signal to detection of the pulse signal by the pulse signal sensing means.
A fluid dielectric constant sensing method comprising the steps of:
- providing a first electrode formed of a conductor being wound as a longitudinal cylinder and a second electrode provided to be separated from a cylindrical surface of the first electrode at a predetermined distance;
- forming a signal transmission line as a distributed constant circuit by the first electrode, the second electrode, and a measured fluid introduced between the first and second electrodes;
- and
- sensing a dielectric constant of the measured fluid based on a change in propagation rate of the signal propagated over the transmission line caused by an affect of the dielectric constant of the measured fluid upon a constant of the distributed constant circuit.
Dependencies are inferred from the claim text.