Digital UV-COD Sensor: Working Principle, Features & Applications
Release time：2026-09-14
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1. What Is a Digital UV-COD Sensor?
A
digital UV-COD sensor is an immersive, reagent-free water quality probe that measures chemical oxygen demand (COD) in real time using ultraviolet absorption. It directly outputs standardized digital signals, enabling networking and system integration without the need for a separate controller. **Jiangsu Lanchuang Intelligent Technology Co., Ltd.** produces this sensor for continuous online monitoring of organic pollution in water.
2. How the UV-COD Sensor Works
2.1 The Lambert-Beer Absorption Principle
The sensor is based on the Lambert-Beer absorption law. High-brightness UV LEDs at specific wavelengths irradiate organic substances in the water sample; the intensity of the absorbed light signal is directly correlated with the organic content. The more organic matter, the more UV light is absorbed.
2.2 Dual-Wavelength Compensation
The sensor measures at 254 nm and 546 nm. COD and SAC254 (spectral absorption coefficient at 254 nm) are the primary parameters, while turbidity is measured as a compensation channel — compensating for the scattering effect of suspended particles on the UV measurement and keeping readings accurate in real water.
2.3 Automatic Compensation for Aging and Fluctuation
The sensor employs a digital and intelligent design concept. A built-in light source intensity reference detection ensures the measurement is unaffected by light source attenuation, automatically compensating for light source fluctuations and component aging on measurement values.
3. Key Features of the Digital UV-COD Sensor
3.1 Digital RS485 Output
The digital sensor outputs RS485 signals with strong anti-interference capability, allowing longer transmission distances and direct integration into monitoring networks without a controller.
3.2 Automatic Cleaning
A mechanical cleaning brush automatically cleans the optical window, significantly reducing maintenance workload and preventing biofouling from corrupting readings.
3.3 IP68 Submersible Design
The probe is rated IP68 with submersion capability to 60 meters, built from stainless steel S316L and POM, weighing just 0.7 kg — suitable for long-term installation in pipes, tanks and open water.
3.4 High Reliability
With an MTBF of at least 1440 hours, a six-month calibration cycle and 0.5 W power consumption (non-cleaning mode), the sensor is designed for low-touch continuous operation.
4. Performance Specifications
|
Parameter |
Specification |
|
Measurement parameters |
COD, SAC254, Turbidity (compensation) |
|
Measurement principle |
UV absorption (254 nm + 546 nm) |
|
Measurement method |
Immersive measurement |
|
COD range |
0–200 / 0–500 / 0–1000 mg/L |
|
Accuracy |
±5% (COD, SAC254), ±5% (turbidity) |
|
Repeatability |
±2% (COD, SAC254), ±5% (turbidity) |
|
Response time |
≤15 s |
|
Calibration cycle |
6 months |
|
Protection level |
IP68, underwater 60 m |
|
Communication |
RS485 (Modbus RTU), max 115200 bps |
|
Power supply |
12/24V DC |
|
Material |
Stainless steel S316L, POM |
5. Applications of Digital UV-COD Sensors
5.1 Sewage Treatment Plants
Continuous monitoring at inlets and outlets to catch organic shock loads in seconds and support process control.
5.2 Surface Water Quality Monitoring
River, lake and reservoir stations where real-time organic load trends are needed alongside periodic laboratory samples.
5.3 Industrial Process Water
Monitoring organic content in industrial wastewater and process water, where early warning prevents permit breaches.
6. How to Select a UV-COD Sensor
- Select the COD range (0–200, 0–500 or 0–1000 mg/L) that matches your water matrix.
- Verify accuracy, repeatability and response time against your monitoring requirements.
- Check the cleaning mechanism — automatic brush cleaning is essential for low maintenance.
- Confirm the communication interface (RS485/Modbus RTU) is compatible with your data acquisition system.
- Review the protection level (IP68) for your installation environment.
7. Conclusion: Why Choose Lanchuang Intelligent
The Lanchuang digital UV-COD sensor combines the reliability of the Lambert-Beer method with digital intelligence and automatic cleaning, delivering one of the lowest-touch real-time organic monitoring solutions in its class. As a national high-tech enterprise with more than 40 self-developed monitoring instruments, Lanchuang can pair this sensor with its multi-parameter stations and cloud platform for a complete water monitoring network.
Contact Lanchuang for range selection and mounting configuration tailored to your water matrix.
