A non-contact method for measuring the frequency-domain dielectric spectrum of composite materials

Abstract

The invention discloses a non-contact method for measuring the frequency-domain dielectric spectrum of a composite material, which comprises the following steps: 1. Input test voltage, frequency range and frequency interval parameters on a dielectric spectrum tester through preset software as required; 2. Place the composite material between the test electrodes, adjust the height of the upper electrode, so that the distance between the electrodes is greater than the thickness of the composite material, that is, there are two dielectrics of composite material and air between the electrodes; 3. Apply frequency conversion voltage excitation to the electrodes, At the same time, the current is measured, and the complex capacitance of the air and the composite material is calculated at the corresponding frequency; 4. The composite material is taken out from between the electrodes, and there is only air as a medium between the electrodes. Apply variable-frequency voltage excitation to the electrodes, measure the current at the same time, and calculate the complex capacitance when there is only air at the corresponding frequency; 5. Calculate the complex dielectric constant and dielectric loss tangent of the composite material according to the formula. It has the advantages of measuring the polarization loss of the material itself and high accuracy.

Description

technical field [0001] The invention relates to a technique for measuring the frequency-domain dielectric spectrum of composite materials, in particular to a non-contact method for measuring the frequency-domain dielectric spectrum of composite materials. The method adopts a non-contact electrode and utilizes air dielectric Spectrum as a reference calibration, combined with a series model of air and composite materials, a method for measuring the frequency domain dielectric spectrum of composite materials. Background technique [0002] Frequency-domain dielectric spectroscopy is an important tool for analyzing the dielectric properties of composite materials. The method measures the material polarization response under the action of an AC electric field, and performs point-by-point or frequency-sweep measurements on different electric field frequencies, so as to obtain the relationship between the complex dielectric constant of the measured object and the measurement frequen...

AI Technical Summary

Problems solved by technology

But these conductive materials face various problems

For example, aluminum is easy to produce oxide layer, silver is easy to migrate in high temperature or high humidity environment, and the cost of gold is too high

Metal foil electrodes are too thin, so it is difficult to determine the size of the electrodes and the thickness of the material

Toothed electrodes can increase the test capacitance of the measured object and improve the surface contact problem, but it is difficult to produce

Liquid electrodes such as mercury and sodium chloride aqueous solutions may be toxic or easily invade the interior of the material when in contact with the surface of the material to be tested, affecting the dielectric properties of the material

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