静力水准系统用于基准高差测量的研究

为了拓展静力水准系统（HLS）在粒子加速器准直测量工作中的应用，开展了针对HLS系统用于多点间基于水平面的基准高差测量的实现方法的研究。基于传感器工作原理，设计并搭建了一套由双频激光干涉仪、高精度位移平台、HLS传感器等组成的比对系统，利用该系统控制多传感器在同一坐标系下观测同一液位。通过比对获得多传感器间基于底部坐标系的零位高度差，实现了多个传感器坐标系间相对于水平面的高差值测量，并验证了高差测量精度优于5 μm。除此之外，通过在HLS传感器上方安装靶座，使用三坐标测量机(CMM)严格标定各传感器电极板至靶球球心的距离，实现了多靶球球心位置基于水平面的高差值测量，并验证了其测量精度优于30 μm。

Research on measurement method of altitude difference using hydrostatic leveling system

As the precise sensor system for monitoring the relative difference in height among multiple points, the hydrostatic leveling system (HLS) is widely used in particle accelerators. At present, the HLS system is mainly used for the measurement of relative altitude changes. To expand the application of HLS system in accelerator alignment, the research on the issue of HLS system for altitude difference measurement based on the horizontal plane between multiple points is carried out. Firstly, the measurement principle of capacitive HLS sensor is introduced briefly. Based on the working principle of the sensor, a comparison system composed of dual-frequency laser interferometer, high-precision Z stage, HLS sensors and others is designed and manufactured. The system is used to control multiple sensors to observe the same liquid level in the same coordinate system. The zero-position difference between multiple sensors based on the sensor coordinate system are obtained by comparison, and the absolute height difference measurement with respect to a hydrostatic surface between the multi-sensor coordinate systems is realized, and it is verified that the measurement accuracy is better than 5 μm. In addition, by installing the target holder above the HLS sensor, and using the coordinate measuring machine (CMM) to strictly calibrate the distance between the sensor surface to the center of the target of each sensor, the absolute height difference measurement of the position of the multi-target centers with respect to the hydrostatic surface is realized, and its measurement accuracy is better than 30 μm.