In order to avoid using very poisonous mercury chloride zinc filament has used iusted of tin dickloride and pollution to environment are reduced and the accuracy of determining results is enhanced.

• 即以锌丝代替氯化亚锡，避免了使用剧毒的氯化汞，减少了对人体的危害和对环境的污染，而且提高了测定结果的准确度。