微位移电容传感电路的噪声分析与实验研究

Experimental Study and Analysis on Noise of Mini-Displacement Capacitance Sensor Circuit

扭杆弹簧倾斜仪是一种结构简单的小型化倾斜仪,可监测地面微小倾斜,广泛应用于工程实践、地球物理和科学实验等诸多领域。本文描述了扭杆弹簧倾斜仪中电容传感电路的原理与构造,理论分析了电容传感电路的热噪声,对电容传感电路的噪声和慢漂特性进行了实验研究。实验结果表明电容传感电路的噪声水平约为0.6mV,折算位移测量的分辨率优于10-10m量级。

Torsion pole spring tiltmeter is a miniature tiltmeter with a simple structure, which can detect floor tilt and be widely applied to many fields such as engineering, physical geography and scientific experiments. The principle and conformation of capacitance transducer circuit used in the torsion pole tiltmeter are described, and the thermal noise in the circuit is analyzed theoretically. Beside it, the noise and performance of slow drift are studied experimentally. The experimental reSult shows that the noise of capaci k tance transducer circuit is about O. 6 mV, and its resolution of the converted displacement measurement is better than the level of 10^-10 m.