提出了测量共焦球面扫描干涉仪精细常数实验方案.该方案利用示波器测量共焦球面扫描干涉仪扫描两相邻透射峰时间Δt2π 及扫描单个透射峰相位半宽度所需时间Δtφ ，共焦球面扫描干涉仪的精细常数为Δt2π 与Δtφ 比值.利用该方案，在不同扫描频率及不同电压下，测量了共焦球面扫描干涉仪精细常数.测量结果表明，在不同锯齿波扫描频率及不同驱动电压下，实验所测得精细常数与厂家所提供理论值趋于一致，实验结果证明该测量方案可靠可行.同时本文对测量数据中，Δt2π 及 　　Δtφ 与扫描频率及扫描电压成反比这一实验现象进行了理论分析.

A scheme of measuring fine constant of confocal spherical scanning interferometer is suggested. In the scheme，the time of scanning the neighboring transmission peak Δt2π and scanning phase half width of one transmission peak Δtφ are measured by the use of oscillograph，and the fine constant of confocal spherical scanning interferometer equals to the ratio of Δt2π and Δtφ . Based on the scheme，the fine constants are measured under different scanning frequency and voltage. The measuring results show that，under different scanning frequency and voltage，the measured fine constants all are close to the theory value of the confocal spherical scanning interferometer provided by the manufacturer，the present measuring scheme is reliable and feasible. Furthermore，it is analyzed in heory that the measured Δt2π and Δtφ are inversely proportional to the scanning frequency and voltage of the saw tooth wave inputting to the confocal spherical scanning interferometer.