Measurement of the Floor Tilt in Experimental Determination of the Gravitational Constant

A prototype of a device with an impact structure for measuring the floor tilt has been built in our laboratory. The mechanical construction and the capacitive transducer of the device are introduced. Experimental results indicate that the floor tilt is about 16#tad in our cavity laboratory, and the uncertainty AG/G caused by such tilt is less than 0.54 parts per million (ppm), so the floor tilt can be reasonably neglected in the experimental determination of the gravitational constant G with the total uncertainty of about l0ppm.     

高精度静电惯性传感器

高精度静电惯性传感器是卫星重力测量、空间引力波探测和航天器微重力测量等应用领域的关键技术之一.本文介绍高精度空间静电惯性传感器的基本工作原理,给出惯性传感器的噪声模型,明确惯性传感器主要指标的设计原则,阐述惯性传感器的地面测试方法,基于惯性传感器敏感探头、检验质量和极板框架的精密结构体系,以及惯性传感器平衡间距、偏置电压、载波电压和反馈电压的参数设计,实现了惯性传感器分辨率10^-8到10^-12m/s²/Hz^1/2量级的性能指标,满足了不同航天任务对惯性传感器量程和分辨率的需求,最后对更高精度的惯性传感器研究进行展望.     

Phase Leading of Temperature Variations in Cavity Caused by Heat Conduction Between Air and Rock

It is well known that the terrestrial temperature varies with the period of 24 hours mainly due to the rotation of the earth in the field of the solar radiation. However, we observed the phenomenon that the semldiurnal(12 hour) temperature oscillation is dominant in our underground laboratory. By the spectrum analysis, the close correlation between the variations of temperature and atmospheric pressure was discovered, and the result of phase analysis showed that the phase of semidiurnal pressure lags behind that of the semidiurnal temperature. A model of heat conduction between air and rock is presented to explain the semidiurnal temperature oscillation observed in the underground laboratory.