In the actual application of water quality monitoring, customers usually monitor multiple parameters of water quality at the same time. The online multi-channel controller MCC200-A4 developed and produced by Daruifuno supports the simultaneous connection of up to 4 digital sensors and displays up to 5 parameters including temperature. At present, the monitoring parameters supported by the multi-parameter controller are: PH, ORP, conductivity, dissolved oxygen, turbidity, COD, ammonia nitrogen, residual chlorine, oil in water, etc. This water quality multi-parameter controller has 3.2-inch LCD display and an RS485 digital interface for data transmission, and supports connection to various industrial control equipment. The multi-channel analyzer has time and historical data recording functions, which can record up to 7800 historical data, and can be used with a USB downloader to download historical data. The advantage of the Multiparameter Controller is that it can match different sensors according to customer needs. When used in surface water monitoring, you can choose online digital pH sensors, digital turbidity sensors, digital conductivity sensors, and digital dissolved oxygen sensors. These four parameters are conventional parameters for surface water monitoring. When used in drinking water monitoring, you can choose a combination of laser low turbidity sensors, residual chlorine sensors and pH sensors.