弹性压缩变形对步距规测量不确定度的影响

Effect of elastic compression on calibration uncertainty of step gauge

针对步距规测量过程中正反向差较大的问题,利用赫兹压力理论分析了测头测力引起的弹性压缩变形,研究表明,由于校准探针用标准器与组成步距规的量块的材质和形状的不同,其弹性压缩变形量存在差异,成为引起正反向差的一个较大分量,通过选择合适的探针校准用标准器,使其符合测量中的一致性原则,可以有效减小步距规的测量不确定度。

In the measurement process of step gauge,forward-backward deviation is a big contribution to the measurement uncertainty.With Hertz＇s contact stress theory,the elastic compression due to probe force is analyzed.The material and shape of the gauge for calibrating probe diameter are different from that of the gauge consisting of step gauge.So the effect of compression on probe diameter is not identical.This leads to the backward-forward error.Through selecting proper probe calibration standards and making them comply with measurement conformity rule,the calibration uncertainty of step gauge will be effectively decreased.