理论实践证明：电光分析天平空重载感量之差超过２０分度，就说明刀口纯度下降，需要同时换下三把刀子。 为电光分析天平换刀是一项比较精细的工作，掌握换刀要领则能事半功倍，否则将事倍功半。 先用天平曲尺及平面尺检查新安装的三把刀子的等臂性、平面性、平行性，反复调整 Theoretical practice shows that: Electro-optical balance balance empty load capacity difference of more than 20 degrees, it shows the edge purity decreased, the need to replace the three knives at the same time. Analytical balance for the electro-optical analytical tool change is a more detailed work, master tool change can do more with less, otherwise it will be less effective. First with the balance ruler and flat feet to check the new installation of three knife arm, flatness, parallelism, repeated adjustments