MEASUREMENT OF DIELECTRIC PERMITTIVITY OF GASES UNDER HIGH PRESSURE IN DECIMETER WAVELENGTH RANGE

Abstract

The paper considers the development of a device for measuring the relative permittivity of high-pressure gases in the decimeter wavelength range. It is shown that the tunable short-circuit at high pressures of the order of several MPa cannot contain nodes of mechanical tuning of the length of the frequency-setting resonator. A method is proposed for tuning the frequency resonator filled with the measured gas by filling the electrolyte between the pairs of dielectric walls inside the resonator. It is indicated that when selecting the electrolyte and the material of the dielectric walls, care should be taken that the electrolyte does not wet the dielectric walls when pouring. The authors carried out an estimated calculation of the concentration of liquid electrolyte and its resistance. The method of measuring the relative dielectric constant of gases under different pressures is described. The results of measurements and the frequency dependences of the relative dielectric constant of the polar gas of NH3 for pressures of 105 Pa and 2 MPa at 300 K are presented.