目的：制备五倍子鞣酸精制品(对照品)及制定质量标准。

Objective: To prepare purified products (reference substances) of tannin from Galla Chinensis and formulate their quality standards.

钢管材质选用碳素钢，活塞杆选用碳钢，油封采用进口高级精制品，耐油，耐磨，耐压，耐腐蚀。

Steel material selection of carbon steel, carbon steel, piston oil imported advanced masterwork, oil resistance, wear-resisting, compression, corrosion resistance.

碳电极、碳刷、灯碳棒、电池碳棒及电气设备用的其他石墨或碳精制品，不论是否带金属。

Carbon electrodes, carbon brushes, lamp carbons, battery carbons and other articles of graphite or other carbon, with or without metal, of a kind used for electrical purposes.