Influence of the environmental noise on determining the period of a torsion pendulum*
Luo Jiea), Tian Yuana), Shao Cheng-Gangb)†, Wang Dian-Honga)
       
(a) The phase difference calculated by the correlation method. (b) Typical variations of the pendulum’s period with respect to time in about three days. In panel (b), the ratio of uncertainty in period to thermal noise limit is 1.8423.