双棱镜测钠光灯波长实验的改进

Improvement of wavelength measurement of sodium lamp with biprism

菲涅尔双棱镜测钠光灯波长实验主要的误差来源是用"大像小像法"测得的狭缝2个虚像的间距d,针对这种情况提出了改良的方案.即选用恰当的双棱镜到狭缝间的距离以增大2个虚像的间距,采用较小的测微目镜到狭缝的距离以增大成小像时读得的狭缝间距d1,以先后测量狭缝两边界位置以确定其中心位置的方法进行测量以减小狭缝的不规则形状带来的误差.

The main error source of Fresnel biprism experiment for measuring the wavelength of sodium lamp is the distance d between two virtual images of the slit measured by big image small image method.In view of this situation,an improved scheme is proposed.That is to say,a proper distance between the prism and the slit is chosen to increase the distance between the two virtual images,a smaller distance between the micrometer eyepiece and the slit is used to increase the distance between the two virtual images of the slitd1,and the central position of the slit is determined by measuring the two boundary positions of the slit successively in order to reduce the error value brought by the irregular shape of the slit.