测量显微镜的光圈直径是影象测量法中影响测值可靠性的重要因素之一。但长期以来对光圈直径只是单一地以被测件的直径变化来选择。近年来国外对此问题进行了不同类别的大量实验,虽未能列出确切的关系图表,但毕竟指出对于“最佳”值的概念应全面地予以考虑。 Measuring the diameter of the aperture of the microscope is one of the important factors affecting the reliability of the measurement in the image measurement method. However, for a long time, the diameter of the aperture has only been chosen to vary with the diameter of the DUT. In recent years, a large number of experiments of different kinds have been carried out in foreign countries. Although the exact relationship chart can not be listed, after all, the concept of the “best” value should be fully considered.