在波尔共振实验中，通过引入两个旋转矢量分别描述受迫振动和强迫力，解决了实验中频闪法测相位差原理阐述 不清的问题. 针对有机玻璃转盘上白线与刻度盘零刻线分别成锐角和钝角的情况，由旋转矢量法分别给出了受迫振动与强迫 力的相位差. 研究发现，无论白线指向刻度盘的哪个区域，受迫振动与强迫力的相位差始终为-π/2 与有机玻璃转盘的白线所 指向角度之差.

We introduce two rotation vectors to describe the forced oscillations and driving force，respectively， and solve the problem that the principle of measurement for phase difference based on stroboscopic method is not clear. The analytical phase difference is obtained by using rotation vector method. We find that the phase difference always shows a difference between π/2 and the angle of the white line in organic glass turntable is pointing to.