YEX-CDOM-406-S Online Chromophoric Dissolved Organic Matter Sensor

The YEX-CDOM-406-S online chromophoric dissolved organic matter sensor (CDOM sensor) launched by Yexsensor is specially designed for real-time and accurate monitoring of chromophoric dissolved organic matter (CDOM) concentration in water. This sensor adopts a mature fluorescence measurement principle, utilizing the absorption and fluorescence emission characteristics of CDOM at specific wavelengths to achieve high-sensitivity detection. Whether in drinking water source protection, wastewater treatment process control, industrial park wastewater discharge supervision, or river and lake ecological environment assessment, the YEX-CDOM-406-S can provide stable and reliable data support, helping users promptly understand the organic pollution status of water bodies and ensure water environment safety and compliance.

As an important member of the Yexsensor online water quality monitoring product line, the YEX-CDOM-406-S is known for its high stability, low maintenance requirements, and convenient installation. It not only effectively filters natural light interference but also features automatic temperature compensation, ensuring long-term stable operation in complex water environments. The sensor adopts a 316L stainless steel housing with an IP68 protection rating, supports submersible installation, and is widely applicable to various water quality monitoring stations, wastewater treatment plants, environmental monitoring departments, and online monitoring systems of industrial enterprises.

YEX-CDOM-406-S Online Chromophoric Dissolved Organic Matter Sensor Core Advantages

The YEX-CDOM-406-S online CDOM sensor fully considers pain points in actual applications during design and possesses multiple leading advantages:

• High-precision fluorescence measurement: Adopts professional UV LED light source to excite CDOM to produce characteristic fluorescence signals. Fluorescence intensity is directly proportional to CDOM content, ensuring high measurement accuracy.

• Excellent anti-interference capability: AC drive technology effectively filters natural light and ambient light interference, maintaining stable readings even in outdoor environments or scenes with large light variations.

• Long service life and low drift: The UV LED light source has a long service life and minimal drift, significantly reducing long-term maintenance costs.

• Intelligent temperature compensation: Built-in Pt1000 temperature sensor automatically performs temperature compensation, ensuring measurement result consistency under different temperature conditions.

• Multiple output methods: Standard configuration RS-485 (Modbus RTU protocol), optional 4-20mA analog output, facilitating integration with various PLC, DCS, data acquisition systems, or host computer software.

• Rugged and durable design: 316L stainless steel housing, IP68 protection rating, can be immersed in water (including seawater) for long periods, with excellent corrosion resistance.

• Low power consumption operation: Only 0.2W@12V, energy-saving and environmentally friendly, suitable for solar-powered or remote monitoring station deployment.

These advantages make the YEX-CDOM-406-S a trustworthy choice in the field of water quality monitoring, helping users achieve the monitoring goal of “install and use, long-term stability”.

YEX-CDOM-406-S Online Chromophoric Dissolved Organic Matter Sensor Working Principle

The YEX-CDOM-406-S chromophoric dissolved organic matter sensor is designed based on the fluorescence method principle. Chromophoric dissolved organic matter (CDOM) has obvious absorption peaks in the ultraviolet spectral region and releases longer-wavelength fluorescence emission peaks after absorbing energy.

When the sensor is operating, the built-in UV LED light source emits monochromatic excitation light of a specific wavelength, which irradiates the measured water body. CDOM molecules absorb the energy of the excitation light and release characteristic wavelength fluorescence when returning from the excited state to the ground state. The sensor receives and measures this fluorescence intensity. Since the fluorescence intensity has a linear positive proportional relationship with the CDOM concentration in the water body, the CDOM concentration can be accurately calculated through the fluorescence signal.

This principle features strong selectivity, high sensitivity, and good resistance to background interference, making it very suitable for online continuous monitoring. Compared with traditional chemical analysis methods, the fluorescence method requires no reagents, produces no secondary pollution, and has a fast response (T90 < 30s), truly achieving real-time online detection.

YEX-CDOM-406-S Online Chromophoric Dissolved Organic Matter Sensor Technical Specifications

YEX-CDOM-406-S Online Chromophoric Dissolved Organic Matter Sensor Typical Application Scenarios

The YEX-CDOM-406-S online chromophoric dissolved organic matter sensor is widely used in various scenarios that require real-time understanding of organic matter content in water bodies:

1. Drinking Water Source Monitoring
          CDOM is an important indicator for assessing organic pollution in drinking water sources. The sensor can be installed at water reservoirs, river water intakes, or water plant inlets to monitor changes in source water quality in real time, detect organic pollution risks from agricultural runoff, industrial discharges, or algal blooms early, and provide data support for water plant process adjustments.

2. Wastewater Treatment Plant Process Control
          In the biochemical treatment section, sedimentation tank effluent, or advanced treatment stages of wastewater treatment, monitoring CDOM concentration helps determine organic matter removal efficiency, optimize process parameters such as aeration volume and chemical dosing, and achieve energy saving, consumption reduction, and stable effluent compliance.

3. Industrial Wastewater Discharge Monitoring
          Wastewater from industries such as chemical, pharmaceutical, printing and dyeing, and food processing often contains large amounts of chromophoric dissolved organic matter. The YEX-CDOM-406-S can be used for online monitoring at total discharge outlets or workshop discharge points to ensure that CDOM indicators meet environmental protection discharge standards after wastewater treatment and avoid over-limit fines.

4. River and Lake Ecological Environment Protection
          In natural water bodies (such as lakes, rivers, and coastal areas), CDOM is closely related to water eutrophication, transparency, and microbial activity. Environmental monitoring departments can use this sensor to build water quality monitoring networks, track long-term changes in aquatic ecology, and provide scientific basis for ecological restoration decisions.

5. Smart Water Management and Online Monitoring Platforms
          The Modbus RTU data output by the sensor can seamlessly integrate with SCADA systems, IoT platforms, or environmental big data centers, enabling remote monitoring, data analysis, alarm linkage, and trend prediction, supporting unmanned smart water environment management.

Whether for fixed monitoring stations or mobile monitoring vessels, the YEX-CDOM-406-S can be easily deployed to meet water quality monitoring needs of different scales and complexities.

Installation and Electrical Connection

Installation Requirements:

The YEX-CDOM-406-S adopts submersible installation and recommends using the 3/4NPT standard thread interface. During installation, please ensure:

• The distance between the sensor and the side wall is kept more than 2cm;

• The distance from the bottom is kept more than 10cm;

• The measurement window is completely submerged in water to avoid the influence of air bubbles or dead zones on measurement.

It is recommended to install the sensor vertically or slightly tilted in an area with steady water flow to obtain more representative water sample data.

Electrical Connection:

The sensor is equipped with a 5-core shielded cable, with clearly defined wire sequence:

• Red wire: Power positive pole (12～24V DC)

• Black wire: Ground (GND)

• Blue wire: RS-485 A

• Green wire: RS-485 B

• Yellow wire: 4-20mA current output (can be left floating when not in use)

Before powering on, carefully check the wire sequence to avoid equipment damage caused by incorrect wiring. It is recommended to perform strict waterproof treatment on all wiring points, especially when used in seawater or corrosive environments. The cable should have good corrosion resistance. Waterproof junction boxes or heat shrink tubing are recommended for protection.

After installation, it is recommended to power on first to observe whether the sensor works normally, and connect to the control system after the reading is stable.

YEX-CDOM-406-S Online Chromophoric Dissolved Organic Matter Sensor Maintenance and Care Guide

The YEX-CDOM-406-S emphasizes low-maintenance characteristics in design, but regular maintenance is still the key to ensuring long-term accuracy.

Daily Maintenance Key Points:

• Measurement window cleaning: Regularly check whether the optical window at the front end of the sensor is contaminated by sediment, biofilm, or oil. Rinse with tap water. For stubborn dirt, gently wipe with a soft cloth dipped in a small amount of household detergent. It is strictly prohibited to use hard objects or strong acid/alkali cleaners.

• Cable inspection: Ensure the cable is not in a stretched state to avoid internal wire breakage caused by long-term pulling.

• Housing cleaning: Regularly rinse the outer surface of the sensor with clean water to keep it clean.

Calibration Method:

The sensor adopts a two-point calibration method:

1. Zero point calibration: Place the sensor in pure distilled water and perform zero point calibration after the value stabilizes.

2. Slope calibration: Place the sensor in a standard CDOM solution of known concentration and perform slope calibration after stabilization.

It is recommended to perform calibration once every 3-6 months according to local regulatory requirements or actual water quality conditions. Calibration commands can be issued via the RS-485 Modbus protocol, and the operation is simple.

There are no user-serviceable parts inside the sensor. If a fault occurs, please contact Yexsensor professional technical support.

FAQ

Q1. Is the YEX-CDOM-406-S suitable for seawater environments?

Yes. The sensor housing is made of 316L stainless steel with an IP68 protection rating, providing good seawater corrosion resistance. It can be used for nearshore, estuary, or seawater aquaculture water quality monitoring. However, it is recommended to enhance cable waterproofing and appropriately increase cleaning frequency.

Q2. How does the sensor avoid natural light interference?

The sensor adopts AC-driven UV LED light source technology, which can effectively filter the interference of ambient light and natural light on fluorescence signals. It maintains stable measurement even under direct outdoor sunlight or drastic light changes.

Q3. What is the lowest CDOM concentration that can be detected?

The minimum detection limit is 0.02 mg/L, and the range covers 0～2.000 mg/L, fully meeting the monitoring needs of most drinking water sources, river and lake water bodies, and wastewater treatment plant effluents.

Q4. Does the sensor require frequent cleaning?

The cleanliness of the measurement window directly affects measurement accuracy. It is recommended to check and clean the window every 1-4 weeks according to the degree of water pollution. The cleaning method is simple and requires no special tools.

Q5. Which data acquisition systems are supported?

The standard RS-485 Modbus RTU protocol is compatible with the vast majority of PLC, DCS, RTU, and IoT gateways. Optional 4-20mA output is convenient for integration with traditional analog acquisition modules.

Q6. Is there a limit to the installation depth?

The working pressure is <0.2 MPa, suitable for most shallow or medium-depth installations. As long as the sensor is fully submerged and more than 10cm away from the bottom, it is fine. For deep-water applications, longer cables can be customized.

Q7. Does calibration require professional personnel to operate?

The operation is very simple. Just prepare distilled water and standard solution, and follow the instruction manual steps for two-point calibration. The entire process is usually completed within 10-15 minutes without complex instruments.

Q8. What is the product warranty period? What to do if a fault occurs?

Yexsensor provides a one-year warranty from the date of sale (excluding man-made damage). If you encounter usage problems, you can contact our technical support team at any time. We will provide quick response and professional solutions, including remote guidance or factory repair.

Why Choose Yexsensor?

Yexsensor focuses on the research, development, and production of online water quality monitoring sensors, always adhering to the product philosophy of “professional, reliable, and easy to use”. The YEX-CDOM-406-S is the result of years of technological accumulation and has undergone strict 72-hour aging tests, stability tests, and environmental simulation tests to ensure that every sensor meets high standards before leaving the factory.

We not only provide high-quality hardware products but also are committed to providing customers with complete monitoring solutions. From model selection consultation and installation guidance to later maintenance and technical support, the Yexsensor team accompanies customers throughout the process to help build efficient and stable water quality monitoring systems.

Take action now:
       If you are looking for an online chromophoric dissolved organic matter sensor with stable performance, convenient installation, and reliable data, the YEX-CDOM-406-S will be your ideal choice. Welcome to contact the Yexsensor sales team to obtain detailed quotations, customized solutions, or on-site demonstrations. We look forward to working with you to jointly protect a clear water environment!