This category specializes in analytical instruments for water quality management in industrial water, cooling water, and wastewater treatment at manufacturing sites. It handles water quality parameter measurement equipment such as pH meters, dissolved oxygen meters, conductivity meters, turbidity meters, residual chlorine meters, COD meters, and BOD meters. These instruments are used for water quality analysis tasks directly connected to manufacturing processes, including cutting fluid quality control, plating solution concentration monitoring, boiler water quality management, and wastewater standard compliance verification. The category covers specialized analytical instruments necessary for factory water quality management operations, from portable field measurement devices to continuous monitoring systems. Distinguished from general environmental measurement equipment and chemical analysis devices, this is a practical measurement instrument group specialized for water quality management in manufacturing industries.