笔者在工作中发现 ,以下外界因素对天平示值变动有很大影响 :１ 震动 :震动的强弱 ,都会引起刀刃在刀承上发生滑动或跳针而改变平衡位置 ,因此天平室应尽量远离震源 ,避免震动。２ 温度 :天平室温度不稳定 ,会使天平横梁臂长不断变化 ,因而示值也随之变化 ,所以天平室应保持恒? The author found in the work, the following external factors on the balance significant changes in the value of a great impact: 1 vibration: the strength of the vibration, will cause the blade in the knife bearing slide or skip and change the balance position, so the balance should be room away from Hypocenter, avoid vibration. 2 temperature: balance room temperature is unstable, will make the balance beam arm constantly changing, indicating the value also will change, so balance room should be kept constant?