端度计量

End Standards Measurement

端度计量是几何量计量的一项基础工作,国内外对量块、量块对和台阶规端度标准器的高精度测量技术开展了大量的研究。量块的测量方法分为比较法和绝对干涉法。比较法介绍了基于高定位重复性测头和干涉比较技术的高精度量块比较仪,其测量不确定度0.04μm+0.4×10^(-6)L。绝对干涉法介绍了量块绝对干涉测量的测量原理及国内干涉测量的发展历程。绝对干涉法主要包括单端和双端量块干涉测量方法,相应地研制了需要研合测量的单端移相量块干涉仪和无需研合的双端移相量块干涉仪,其测量不确定度达到15 nm+0.15×10^(-6)L。以移相量块干涉仪为基础开展了量块对和台阶规的测量方法研究。为实现量块对的高精度测量,通过不确定度分析和实验验证获得并规定了单端移相量块干涉仪测量量块对的限定测量条件。采用移相量块干涉仪测量量块对长度差的测量不确定度不超过10 nm。采用单端移相量块干涉仪可以实现台阶规的高精度测量,通过对干涉条纹的分析计算,台阶中心高度测量不确定度达到(0.01~0.1)μm。为满足超高精度的长度测量的需求,研究超高精度干涉测量技术是端度计量的发展趋势。已有的单端和双端移相干涉技术为基于全新设计的超高精度干涉仪的研制奠定了基础,从而实现纳米级测量不确定度的端度测量。

End standards measurement is a fundamental aspect of geometric metrology.Extensive research has been conducted on the high-precision measurement of gauge blocks,gauge block pairs,and step height gauges both domestically and internationally.Gauge block measurement methods are divided into comparison and absolute interference methods.The comparison method involves a high-precision gauge block comparator,utilizing a probe with high positioning repeatability and interference comparison technology,achieving a measurement uncertainty of 0.04μm+0.4×10^(-6)L.The absolute interferometry method discusses the principle and historical development of gauge block absolute interferometry in China.This method encompasses both single-ended and double-ended gauge block interferometry techniques,leading to the development of single-ended phase shifting and double-ended phase shifting gauge block interferometers.These devices attain a measurement uncertainty of 15 nm+0.15×10^(-6)L.Research on phase shifting interferometers laid the foundation for gauge block pair and step height gauge measurements.High precision measurement of gauge block pairs was achieved under specified conditions determined through uncertainty analysis and experimental validation,with measurement uncertainty not exceeding 10 nm.Single-ended phase shifting interferometers enable high-precision measurement of step height gauges,with center height measurement uncertainty reaching(0.01~0.1)μm.To meet ultra-high precision length measurement needs,research on ultra-high precision interferometry technology is identified as the future trend in end standards measurement.Existing single-ended and double-ended phase shifting interferometry technologies pave the way for developing ultra-high precision interferometers,thereby achieving nanoscale measurement uncertainty in end standards measurement.