1.Product Introductions

The COD Sensor is a digital sensor featuring an easy-to-integrate RS485 communication interface and standard Modbus protocol. It is equipped with a corrosion-resistant housing, IP68 protection rating, and a built-in self-cleaning brush for periodic cleaning of the measurement interface, making it suitable for harsh working environments. Utilizing long-life LED light sources and beam measurement technology, it ensures high measurement precision and stability.

2. Operation Principle

The fundamental measurement principle of the UV254 absorption method is based on the absorption of ultraviolet (UV) light by organic compounds in water samples to determine their content and composition. Specifically, the UV absorption method involves directing UV light at a specific wavelength (254nm) into the water sample. The absorbance value obtained is then used to calculate the Chemical Oxygen Demand (COD) concentration in the water. This calculation relies on the Lambert-Beer Law, which serves as the foundational theoretical framework for measuring the absorbance of substances.

3. Electric Connection

The cable is a 4-core twisted-pair shielded wire with the following pinout:

 Red wire: Power supply (12–24 VDC)
 Black wire: Ground (GND)
 Blue wire: 485A
 White wire: 485B
Before energizing the device, thoroughly verify the wiring sequence to prevent damage resulting from incorrect connections.Given that the cables may be submerged in water (including seawater) or exposed to air for extended periods, they must possess corrosion-resistant properties. Additionally, all connection points must undergo waterproof sealing to ensure long-term reliability

4. Installation Instructions

4.1 Installation Precautions

 Avoid exposing the sensor to direct sunlight
 Do not touch the measurement area of the sensor with bare hands
 Ensure the sensor surface is free of air bubbles during measurement and calibration
 Avoid applying mechanical stress (pressure, scratches, etc.) to the sensor during use