Capacitance sensor
OwnerDavid Riceinventor
Life of this patent
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Abstract
A capacitance sensor includes flexible interdigitated electrodes and an uncomplicated, compact control circuit including a frequency meter, a resistance capacitance oscillator, a display, and a microcontroller to manage these components. In an exemplary method of use of the capacitance sensor to monitor known parameters of a fluid, the flexible electrodes may be inserted into a circular tubular conduit containing the fluid. As fluid flows past the electrodes, any discrepancies from the known parameters may be detected and signaled immediately.
Claims13
A capacitance sensor for sensing contaminants and undesired concentrations of substances in a fluid being monitored and contained within a vessel, the capacitance sensor comprising:
- a flexible substrate bearing
- two electrodes spaced apart from one another by gaps, wherein each of the electrodes has a width in plan view, and each of the gaps has a width in plan view greater in magnitude than the width of the electrodes,
- dielectric material between the two electrodes, and
- electrical insulation covering the two electrodes;
- and
- a control circuit comprising:
- a source of electrical input signals connected to the two electrodes;
- a frequency meter in frequency sensing relation to the two electrodes;
- a display for annunciating capacitance values;
- and
- a microcontroller arranged to process capacitance signals from the frequency meter and to generate responsively signals indicative of determined capacitance values from the capacitance signals.
A method of rapidly determining an unacceptable parameter of water within a vessel having an internal configuration, the method comprising the steps of:
- establishing a predetermined capacitance value for pure water;
- using a capacitance sensor having a flexible substrate bearing two interdigitated electrodes, forming the flexible substrate and interdigitated electrodes into a configuration complementing that of the vessel and inserting the flexible substrate and interdigitated electrodes into the vessel in contact with internal surfaces of the vessel;
- and
- monitoring capacitance of fluid flowing in the annular fluid conduit for a discrepancy from the predetermined capacitance value of pure water;
- and
- issuing a signal immediately, responsive to detecting the discrepancy from the predetermined capacitance value of pure water.
Dependencies are inferred from the claim text.