光干涉法高精度材料线膨胀系数测量  

Thermal Expansion Coefficient Measurements with Precision Interferometer

作　　者：张旭东[1] 苏永昌[1] 叶孝佑[1] 

机构地区：[1]中国计量科学研究院,北京100013

出　　处：《计量学报》2012年第1期1-4,共4页Acta Metrologica Sinica

基　　金：科技部基础条件平台项目（PT0709-3）

摘　　要：中国计量科学研究院研制的高精度材料线膨胀系数测量装置，满足温度范围为5～40℃、被测件长度在20～1000mm之间的线膨胀系数测量。采用激光干涉法测量被测件长度变化量，用高精度温度传感器测量温度值。设计了热平衡式干涉镜，利用空气折射率修正和零位误差补偿技术，保证在5～40℃变温范围内激光干涉仪的测量精度。以500mm标准量块作为测量对象，线膨胀系数测量结果与德国物理技术研究院（PTB）测量结果的相对偏差为0．2％。材料线膨胀系数测量不确定度达到3×10^-8K^-1。The thermal expansion measurements with NIM＇ s precision interferometer are described. The measurements are based on the observation of the length change of the material samples as a function of a temperature using laser interferometry. The interferometer and the material sample up to 1 m are situated in a tight enclosure which temperature is controlled by a water circulation within a temperature range from 5℃ to 40℃. A heat-balanced interference mirror was designed. A high precision temperature measuring system is used for measuring the temperature of the material sample and the air. The accurate determination of the refractive index of air and the real-time compensation of zero error are accomplished. Using an 500 mm gauge block, thermal expansion coefficient is measured with a relative deviation of less than 0. 2% , and it was compared with those of Physikalisch-Technische Bundesanstalt （PTB） of Germany. The coefficient of thermal expansion can be obtained with a uncertainty less than 3×10^-8K^-1.

关 键 词：计量学 线膨胀系数 激光干涉测量 空气折射率 不确定度 

分 类 号：TB92[一般工业技术—计量学]