This paper introduced the basic control mode of automatic control system of coagulant dosage,taking the technique of streaming current defection for example, and then the merits and demerits of each control mode and the applicability was analyzed.

• 以流动电流检测技术为例，介绍混凝投药自动控制系统的基本控制方式，并且对各种控制方式的优缺点及适用条件作了分析。