Abstract: During the teaching of measuring the moment of inertia of a rigid body using a three-wirependulum，it was observed that students often set the swing angle of the lower disk either too large or too small．Meanwhile，phenomena such as transverse swing and wobbling occurred in the lower disk．Based on an analysisof the experimental principles and three-wire pendulum，a scheme to improve the three-wire pendulum isproposed．First，the rotation angle of the driving disk is visualized by calibrating scales，which provides areference for the swing angle of the lower disk．Second，the principle of a plumb line is utilized to level thedriving disk．The improved setup not only facilitates adjustment but also reduces measurement errors．
张瑞芳 , 崔钰洲 , 赵婷婷, 韦 仙, 杨文锦. 基于铅垂线原理的三线摆实验仪研究[J]. 大学物理实验, 2026, 39(1): 79-83.
ZHANG Ｒuifang, CUI Yuzhou, ZHAO Tingting, WEI Xian, YANG Wenjin. Ｒesearch on the Three-Wire Pendulum ExperimentalInstrument Based on the Plumb Line Principle#br#. Physical Experiment of College, 2026, 39(1): 79-83.
