METHOD OF MEASUREMENT complex permittivity of liquid and granular substances

摘要

^FIELD: measurement equipment.;SUBSTANCE: in the method to measure complex dielectric permeability of liquid and loose substances in wide range of frequencies in one cell used in the range of frequencies of higher than 100 MHz as a section of a coaxial line, and in the range below 1 MHz as a cylindrical condenser. In the range of frequencies above 100 MHz the dielectric permeability is calculated via measured values of the complex coefficient of transfer of electromagnetic wave (parameter of scattering matrix S12), and in the range of frequencies below 1 MHz - via measurement of full conductivity, the novelty is the fact that for measurements in the frequency range of 0.3-100 MHz an additional section of the coaxial line is used with wave resistance of 50 Ohm and section larger than in a cell, the inner diameter of the external conductor of which is determined in accordance with the formula $D_1=d_1\exp \left(\frac{Z_{01}}{60}\right),$ where d₁ - external diameter of the cell body; Z₀₁ - wave resistance of the additional section of the coaxial line, in which the cell is placed, at the same time the cell is connected as the cylindrical capacitor into the gap of the internal conductor of the additional section of the coaxial line, having two microwave slots, to central conductors of which a central conductor of the cell is connected at one side, and at the other side - the cell body via the matching adapter in the form of a section of the conical line with wave resistance 50 Ohm, and its calibration is carried out, for this purpose they determine parameters of the equivalent circuit of the additional section of the coaxial line with an empty cell arranged in it. Then the cell is filled with the investigated substance, and in the range of frequencies of 0.3-100 MHz they measure the complex coefficient of transfer (parameter of scattering matrix S12), and using the formulas that relate CDP with the S12 parameter, they determine CDP.;EFFECT: method for measurement of CDP provides for its measurement in one cell with low error in the entire frequency range from 1 kHz to 6000 MHz.;9 dwg