The design of online system for multi-rang measuring sediment concentration

According to actual sediment testing needs, an online system is designed to measure sediment concentration. In this system, two testing ways will be selected at the different sediment range. When the water contain low sediment, the system will chose photoelectric-based detection methods to measure. It has a low measurement range, but has a high accuracy. When the water contain high sediment, the system will chose capacitive differential pressure detection methods to measure. On the contrary, it has a lower precision, but has higher measurement range. This paper particularly introduces photoelectric testing technology, principle of the capacitive differential pressure sensor, PLC hardware design, sensor inclination correction and monitoring software design. The system can overcome the effects of different environments, and work steadily. This system is more suitable to measure sediment concentration in the reservoir dredging, water quality management and slurry treatment etc.