JPS56124039A - Dielectric sensor - Google Patents

Abstract

PURPOSE:To enable measurement of dielectric constant, density, size, mass, etc. of the dielectric without any restriction to the shape of the dielectric or the like by providing conductor plates on the outer peripheries of the end parts of a pair of waveguide pipes whose opening ends are opposed to each other and thereby forming the dielectric sensor. CONSTITUTION:The dielectric sensor 1 is formed by fitting the conductor plates 3 on the outer peripheries of the waveguide pipes 2 whose opening ends are opposed to each other and by providing an aperture 4 through which the dielectric to be measured can be inserted between the conductor plates 3, while a microwave is passed into the pipes form one of the waveguide pipe 2, and the aperture 4 between conductor plates 3 is determined properly, whereby a kind of resonator is constituted. And, when a dielectric material having some dielectric constant is put into the aperture 4 between the conductor plates 3 forming the resonator, equivalent dielectric constant becomes higher than that before putting and the resonant frequency is shifted toward low level. Accordingly, when dielectrics having the same size but unknown dielectric constant respectively are put into the aperture 4, respective resonant frequency becomes known, the dielectric constant of the dielectric which is put in can be calculated, and when the dielectrics having the same dielectric constant but being different in size are put into the aperture 4 respectively, the sizes thereof are known.