Electromagnetic resonant sensor with dielectric body and variable gap cavity

• Main Author: FRICK ROGER L
• Format: Patent
• Language: English
• Published: 12.02.2008
• Subjects: ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; BASIC ELECTRONIC CIRCUITRY; CONTROLLING; ELECTRICITY; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER,MECHANICAL EFFICIENCY, OR FLUID PRESSURE; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; MEASURING QUANTITY OF HEAT; MEASURING TEMPERATURE; MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUIDLEVEL; METERING BY VOLUME; MODULATION; PHYSICS; REGULATING; SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES; TARIFF METERING APPARATUS; TESTING; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR

An electromagnetic resonant sensor has a dielectric sensor body through which electromagnetic wave energy is propagated. The sensor body has a cavity, with surfaces facing one another to define a gap that varies as a function of a parameter to be measured. The resonant frequency of an electromagnetic standing wave in the body and the variable gap changes as a function of the gap dimension.