低纬子午环的轴准直器与枢轴不规则的测定

本文论述了因枢轴不规则和两个叉臂的温差引起水平轴指向漂移的影响；详细叙述了用轴准直器测定和修正这种影响的方法；并且给出了测定轴准直器参数的方法。精度估计表明，在低纬子午环上使用了电水准器和轴准直器后，对枢轴的加工精度降低了一个数量级，并且降低了对轴系稳定性的要求，然而测量和修正这些误差的精度却是很高的。

Determination of the Irregularity of the Horizontal Axis with the Axis-Collimator

In this paper, the influence of the horizontal axis point's drifting is described, which is caused by the irregularity of the axis and the difference betweent the temperatures of the two hands. The method is recounted for determining and correcting the error with the axis-collimator. Meantime, it is discussed how to determine the parameters of the axis-collimator. The estimate of the accuracy shows that when the electric-collimator and axis-collimator are used in the Low latitude Meridian Circle, the machining accracy of the axis and the stability of the axis system may be lower while the accuracy for the determination and correction of these errors is very high.