天平的示值变动性是指在相同条件下多次开启天平后的停点均不在一个平衡位置上。影响天平示值变动性的基本原因是 ,由于所能观测到的天平合力矩的改变 ,从而引起平衡位置发生微小改变 ,进而引起天平合力矩改变 ,其原因是多方面的 ,具体概括如下 :１ 外界环境条件的影响（１）温 The balance of the indicator change is the same conditions in the open balance after several stops are not in a balance position. The basic reason for the change in the indication of the balance is that the observable change in the balance of moments results in a slight change in the equilibrium position, which in turn causes the change in the balance of moments. The reasons are numerous and can be summarized as follows: 1 The impact of external environmental conditions (1) temperature