Material low-temperature linear expansion coefficient optical test system and test method

Abstract

The invention relates to a material linear expansion coefficient test system, in particular to a material low-temperature linear expansion coefficient optical test system and test method. The test system is characterized by comprising an ultralow-temperature demisting temperature control box, an image acquisition device, an upper computer and a temperature control device; the image acquisition device is used for acquiring tested sample images of different temperature points; the upper computer is connected to the image acquisition device and is used for acquiring the sizes of tested samples atdifferent temperature points according to the images of the tested samples at different temperatures, and the data processing module is used for solving a temperature-size equation according to the sizes of the tested samples at different temperature points and deriving the equation to obtain a linear expansion coefficient. The temperature control box is utilized, the image acquisition device utilized to acquire the size change of the tested sample in the testing process through the window, the low-temperature linear expansion coefficient of the tested sample is calculated through the image processing module and the data processing module, the accuracy is high and the system is flexible and efficient.

Description

technical field [0001] The invention relates to a material linear expansion coefficient testing system, in particular to an optical testing system and a testing method for the material's low temperature linear expansion coefficient. Background technique [0002] The vast majority of materials have the characteristics of "thermal expansion and contraction", which is caused by the intensification or weakening of the thermal motion of molecules within the material. This property should be considered in the design of engineering structures, in the manufacture of machinery and instruments, in the processing of materials (such as welding), and in the insulation of materials (such as LNG insulation). Otherwise, the stability of the structure and the accuracy of the instrument will be affected. [0003] The low temperature linear expansion coefficient is the numerical expression of the "cold shrinkage" characteristic of the material, which can be characterized by the average low te...

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Problems solved by technology

The low-temperature test chamber method mainly uses liquid nitrogen vaporization to cool down, and after liquid nitrogen vaporization produces water mist in the test chamber, testers cannot directly detect the low-temperature linear expansion coefficient of the tested sample, and can only use the contact indirect method to measure hard materials The low-temperature linear expansion coefficient is complicated and the accuracy is low; the ejector pin test method has more requirements on the sample, and it is only suitable for the determination of the average linear expansion coefficient of hard materials in the low-temperature field.

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