Method for detecting electrical conductivity of small number of solids

Abstract

The invention discloses a method for detecting the electrical conductivity of a small number of solids. The method comprises the following steps that two metal nail-shaped electrodes are used for limiting detected powder in a PTFE pressure-bearing pipe, wherein the height of the pressure-bearing pipe ranges from one centimeter to three centimeters, and the diameter of the pressure-bearing pipe ranges from three millimeters to five millimeters; in the measuring process, pressure is exerted on the metal nail-shaped electrodes at the two ends, air among the powder is exhausted, and the powder is squeezed into a cylinder; the length of an inner cylindrical sample can be measured through a measuring tool, and the overall resistance is measured through a multimeter; the electrical conductivity is calculated; after measurement is completed, the metal nail-shaped electrodes are pulled out of the two ends of the pressure-bearing pipe, and the sample is ejected out of the pressure-bearing pipe through a hard needle. According to the method for detecting the electrical conductivity of a small number of solids, only a small number of samples are used, and accurate measurement data of the electrical conductivity are obtained through a very simple method on the premise that no liquid auxiliaries need to be added and no properties of the powder are changed.

Description

technical field [0001] The invention relates to a method for detecting the conductivity of trace solids. Background technique [0002] In modern scientific research, the research scope of many researchers involves the detection of the conductivity of solid powder or fiber. The commonly used method in the experiment is to prepare the powder into a solution or suspension, and use the existing conductivity meter for measurement. There are two problems with this measurement, the first is that the accuracy is not high, because the result of this method depends largely on whether the solvent conductivity is good, the solubility of the powder and whether its concentration in the solution can form itself in the solvent The electronic conduction network of the solvent will affect the conductivity of the solvent, thereby affecting the detection results; secondly, it is not universal, because this method will encounter problems when it is used to measure fibers and other research obje...

AI Technical Summary

Problems solved by technology

There are two problems with this measurement, the first is that the accuracy is not high, because the result of this method depends largely on whether the solvent conductivity is good, the solubility of the powder and whether its concentration in the solution can form itself in the solvent The electronic conduction network of the solvent will affect the conductivity of the solvent, thereby affecting the detection results; secondly, it is not universal, because this method will encounter problems when it is used to measure fibers and other research objects that are completely insoluble and cannot form a suspension. If you add a surfactant to prepare a suspension, you need to exclude the influence of the surfactant on the overall conductivity. If you don’t add it, the liquid and the solid will be separated, and the conductivity meter will only measure the conductivity of the liquid; the last is Difficult sample recovery, after mixing with liquids and even surfactants, it takes a lot of work to remove the liquid and additives attached to the powder

[0003] In addition to the method of using solution measurement, there is another method that uses a tablet press or similar device to press a large amount of powder into thin sheets, and then uses the four-probe method or directly through a special device for measurement. Under the plane measurement, it is difficult to distinguish the volume conductivity or the surface conductivity, and the cost of this method is very high. There are also instruments that can be directly measured after tableting, but it requires a relatively large number of samples to be measured. For some cost comparisons High powder, unable to provide a large number of samples at one time, not suitable for this method

At the same time, equipment such as tablet presses are often bulky and not suitable for portable use

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