Liquid dielectric constant measuring method

Abstract

The invention relates to the field of material research, and provides a liquid dielectric constant measuring method. A liquid sample to be measured is added into a sample tank. A through hole in the sidewall of a lower part of a resonator outer conductor is completely immersed in the liquid sample. A high voltage direct current power supply is turned on. The high voltage direct current power supply outputs voltage to a high voltage switch through a charging resistor, a charging line and a pulse shaping cable, and the voltage is typically in the range of 1.2kV to 2.0kV. The output voltage of the high voltage direct current power supply is adjusted to close the high voltage switch. An oscilloscope monitors the voltage waveform of the output end of the high voltage switch. When the high voltage switch is closed, a voltage difference is generated between the core of a transmission line II and a sample slot casing and is applied to the liquid sample. A vector network analyzer outputs a microwave signal and enters a resonator through an SMA connector. The vector network analyzer records the resonance frequency of the liquid sample. Data collected by the vector network analyzer are inputto a computer and are processed by the computer to acquire a reflection spectrum, and the dielectric constant of the liquid sample is calculated.

Description

technical field [0001] The invention relates to the field of material research, in particular to a liquid dielectric constant measuring method capable of measuring the dielectric constant of a liquid sample subjected to high voltage action. Background technique [0002] Many chemical and biological applications need to accurately measure the dielectric constant of liquids. Refractive index sensors are used in the prior art to measure, but the refractive index response is not linear, which requires a cumbersome calibration process. In addition, the refractive index sensor is not sensitive to bending It is very sensitive, so interference signals will be collected in the characteristic spectrum of refraction measurement. There are also existing technologies that use reflective refractometers to measure the dielectric constant of liquids, but reflective refractometers are relatively fragile, with high manufacturing costs and complicated processes. The two reflective surfaces mus...

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Problems solved by technology

[0002] Many chemical and biological applications need to accurately measure the dielectric constant of liquids. Refractive index sensors are used in the prior art to measure, but the refractive index response is not linear, which requires a cumbersome calibration process. In addition, the refractive index sensor is not sensitive to bending It is very sensitive, so interference signals will be collected in the characteristic spectrum of refraction measurement. There are also existing technologies that use reflective refractometers to measure the dielectric constant of liquids, but reflective refractometers are relatively fragile, with high manufacturing costs and complicated processes. The two reflective surfaces must be precisely machined to keep them parallel, and these imperfections affect their performance in practical applications

In the experiment of studying the liquid after the action of high voltage, it is necessary to apply a voltage pulse with a certain amplitude and duration to the liquid, but the device in the prior art has a large volume and is inconvenient to operate. The method for measuring the dielectric constant of a liquid able to solve problems

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