China COD Sensor Suppliers & Factory

BOQU is a verified manufacturer founded in 2007. Operating two comprehensive production and calibration facilities in Kangqiao and Lingang, Shanghai (spanning 4,632 m²), we handle mechanical fabrication, cleanroom optical assembly, SMT electronics mounting, 48-hour continuous sensor burn-in, and ISO 9001 certified laboratory calibration in-house.

Many organic molecules containing aromatic rings and conjugated double bonds absorb ultraviolet energy at 254 nm. Under stable industrial conditions, the Lambert-Beer law establishes a strict linear or polynomial correlation between UV absorption and chemical oxygen demand. By running a 5-point local baseline calibration against certified laboratory digestion samples, the optical probe mirrors standard laboratory results in real time with over 95% statistical accuracy.

Path length selection is governed directly by expected concentration ranges. For pristine surface water and drinking water sources (0–100 mg/L COD), an optical path of 10 mm to 50 mm is specified to ensure high photometric sensitivity. For municipal secondary effluent (0–500 mg/L COD), a 5 mm path is optimal. For untreated industrial wastewater or high-strength influent (up to 5,000+ mg/L COD), a narrow 1 mm or 2 mm optical gap prevents complete light saturation.

BOQU optical COD probes offer two automated maintenance systems: an integrated motor-driven silicone wiper blade that periodically cleans the optical quartz window, or an integrated high-pressure compressed air / water jet nozzle. Both systems prevent microbial bio-fouling and mineral scaling, extending autonomous maintenance cycles beyond two months.

Yes. Our IoT-enabled digital sensors incorporate an onboard microprocessor outputting standard Modbus RTU over an isolated RS485 physical interface. They communicate directly with standard PLCs, DCS systems, RTUs, and cellular IoT gateways on 12–24V DC power without requiring costly proprietary display controllers.