Biochemical oxygen demand sensor Achieves Online Monitoring of Multiple Water Quality Indicators Using Dual Light Sources

Biochemical oxygen demand sensor employs a UV254 dual-light source detection system, automatically handling turbidity and temperature compensation. BOD values are calculated from COD, allowing for simultaneous monitoring of multiple water quality indicators. It is suitable for online monitoring of wastewater and river water quality.

Biochemical oxygen demand sensor utilizes a UV254 absorption method dual-light source measurement structure. The device internally houses two independent light sources: one dedicated to COD detection, and the other for turbidity acquisition. The probe simultaneously collects water temperature data and performs temperature compensation calculations. BOD values are calculated from COD data using a built-in algorithm, enabling a single probe to simultaneously monitor three water quality indicators.

Dissolved organic matter in water can absorb 254nm ultraviolet light. The sensor calculates the COD concentration by detecting changes in the transmittance of the light source as it passes through the water. A separate turbidity optical path captures light loss caused by suspended particles in the water in real time, automatically compensating for turbidity in the COD detection results to eliminate data interference from turbid water. A temperature sensor continuously collects the on-site water temperature, correcting measurement deviations caused by temperature changes and improving data stability under complex conditions. This sensor has a default COD measurement range of 0-1000 mg/L, a BOD range of 0-400 mg/L, a turbidity detection range of 0-400 NTU, a COD and BOD resolution of 0.1 mg/L, and a turbidity resolution of 0.1 NTU. The overall measurement accuracy reaches ±5%, and the temperature detection accuracy is ±0.3℃, meeting the detection requirements of most conventional wastewater and surface water.

Traditional water quality monitoring projects require the separate installation of multiple independent monitoring devices for COD, turbidity, and BOD. This results in high equipment procurement costs, cumbersome on-site wiring, installation, and commissioning processes, and the need for separate maintenance of different probes later on. Biochemical oxygen demand sensor integrates multiple detection units, simplifying on-site equipment deployment. The probes output standard digital signals, allowing direct connection to water quality monitoring platforms and PLC control systems. It can be directly deployed to locations such as sewage outlets, wastewater treatment ponds, and river networks. The reagent-free optical detection method does not generate secondary pollutants, and the overall maintenance workload is lower compared to chemical detection equipment. It is suitable for projects requiring long-term, uninterrupted in-situ water quality monitoring, providing continuous and reliable raw monitoring data for water environment management.