China UV BOD Sensor Manufacturer & Factory Pricelist

Biochemical Oxygen Demand ($BOD$) measures the oxygen consumed by bacteria oxidizing organic matter. In most municipal and industrial wastewaters, the predominant biodegradable organic constituents contain aromatic rings and conjugated double carbon bonds that strongly absorb ultraviolet radiation at 254 nm. By establishing a baseline linear or polynomial correlation curve ($BOD = a \cdot SAC_{254}^b + c$) calibrated against standard accredited laboratory $BOD_5$ dilution tests, the sensor provides real-time surrogate values with typical correlation coefficients ($r^2$) ranging between 0.90 and 0.98.

Optical path selection depends directly on the expected organic concentration and turbidity of the sample stream to remain within the linear absorbance range of the photodiode (typically 0.01 to 2.5 AU). For clean surface water and final drinking water effluent ($BOD < 15\text{ mg/L}$), a long path length of 10 mm to 20 mm is specified. For municipal secondary effluent and treated industrial discharge ($BOD$ 10–200 mg/L), a 5 mm path is optimal. For heavy municipal influent, dairy wastewater, or brewery pretreatment ($BOD > 500\text{ mg/L}$), a narrow 1 mm or 2 mm gap must be used to prevent optical saturation.

Yes, particulate matter causes physical light scattering that falsely mimics light absorption. BOQU overcomes this limitation by implementing a dual-wavelength optical bench. While the primary UV LED measures total absorption plus scattering at 254 nm, a second reference wavelength in the green/infrared spectrum (typically 550 nm or 860 nm)—where dissolved organics do not absorb—measures pure turbidity scattering. The onboard microprocessor subtracts the scattering vector mathematically, isolating pure dissolved organic absorbance.

Traditional xenon flash lamps require replacement every 12 to 18 months and draw significant current. BOQU utilizes state-of-the-art solid-state deep-UV LEDs with continuous operational lifespans exceeding 30,000 hours (over 5 years in pulsing duty mode). Routine maintenance consists of monthly inspection of the sapphire windows and wiper blade wear, with calibration zero-drift verification performed quarterly using distilled deionized water.

All BOQU sensors include a comprehensive 12-month factory warranty against manufacturing and optical defects. Standard configurations (316L, 2mm/5mm path, Modbus RS485) typically dispatch within 3 to 7 working days from our Shanghai warehouse. We deliver worldwide via DHL, FedEx, and air freight with complete export documentation, including Certificate of Origin (CO), CE Declarations, and factory QA test certificates.