测定度盘对径改正的要求和条件

The Requirements for Determining the Pair-radius Correction of the Circle

介绍了低纬子午环的度盘、读数显微镜及其读数系统的配置情况，论述了测定每条对径改正的必要性，并从对径读数中所含的误差，分析了在未对度盘和读数显微镜的装调提出苛刻要求的条件下，如何将度盘对径改正和其他误差影响一道测定出来，对对径读数作修正，以保证度盘读数的高精度。

Some information about the circle, the reading microscopes and the corresponding reading system of the LLMC is given in this paper. The necessity to determine each pair-radius correction is expounded from the angle of the classification of the circle division error. It is analyzed from the composition of the error contained in the circle reading that the influence of the circle pair-radius division error, the installation error between the circle and the reading microscopes could be determined together to correct the circle reading by using the method of fixing the angular distance, i. e., the relative position between the reading microscopes and the circle is kept as constant in the course of determining correction, observing and reading on the condition that no strict requirements are set on the assembly of the circle and reading microscopes.