YEX-COL-408-S Online Color Sensor

The YEX-COL-408-S online color sensor launched by Yexsensor is a high-performance digital sensor specially designed for real-time monitoring of water color. This sensor adopts advanced dual-wavelength visible light absorption method. It accurately captures the absorption degree of visible light by water through the 470nm main measurement optical path, while using a reference optical path to compensate for turbidity interference, achieving simultaneous and accurate measurement of color and turbidity.

Water color is an important indicator for evaluating the sensory quality and organic pollution of drinking water, industrial water, and natural water bodies. The YEX-COL-408-S can be directly immersed in water for continuous online operation without chemical reagents, truly achieving green environmental protection and low operating costs. It is compact, easy to install, and equipped with a built-in self-cleaning brush that effectively prevents biofilm attachment. It maintains excellent stability and low drift characteristics even during long-term continuous monitoring.

As an important part of the Yexsensor online water quality monitoring product line, the YEX-COL-408-S widely serves municipal water supply, wastewater treatment, industrial environmental protection, and ecological monitoring fields, helping users quickly detect water quality abnormalities, optimize treatment processes, ensure compliance with discharge standards, and provide reliable data support for water environment management and safe production.

YEX-COL-408-S Online Color Sensor Core Advantages

The YEX-COL-408-S online color sensor demonstrates multiple outstanding advantages in practical applications:

• Dual-wavelength compensation technology: One visible light path measures color, and one reference light path compensates for turbidity. The algorithm effectively eliminates interference from suspended particles, making measurement results more stable and reliable.

• Self-cleaning design: Equipped with a reliable cleaning brush that automatically prevents biofouling and dirt accumulation, significantly reducing the frequency of manual maintenance.

• Multi-parameter simultaneous measurement: Simultaneously outputs color, turbidity, and temperature data. One sensor meets multiple monitoring needs.

• High stability and fast response: Low drift, response time <30s, maintaining precise measurement for a long time even in complex water quality environments.

• Digital intelligent output: Standard RS-485 Modbus/RTU protocol, easy to integrate with SCADA, PLC, and IoT platforms. Optional 4-20mA analog output is available.

• Low power consumption and strong protection: Power consumption only 0.2W@12V, 316L stainless steel housing + IP68 protection rating, suitable for long-term immersion (including seawater environments).

• Reagent-free, environmentally friendly and economical: No chemical reagents required, reducing secondary pollution and operating costs, with a long service life.

These design features make the YEX-COL-408-S an ideal choice with high cost-performance, easy deployment, and easy maintenance in water quality monitoring projects.

YEX-COL-408-S Online Color Sensor Working Principle

The YEX-COL-408-S online color sensor works based on the dual-wavelength visible light absorption method principle.

The sensor has two built-in light paths: the main measurement optical path uses 470nm wavelength visible light to irradiate the measured water body. Colored substances in the water selectively absorb this wavelength light, causing the transmitted light intensity to attenuate. The sensor measures this attenuation through a precision photoelectric detector and calculates the color value (unit: Hazen) according to the Lambert-Beer law.

At the same time, the reference optical path uses another wavelength light source, mainly to monitor the overall attenuation effect of water turbidity on the optical path. Through a specific algorithm for real-time compensation of the two signals, it can effectively subtract interference from non-color factors such as suspended particles, ensuring that the color measurement result is not affected by turbidity fluctuations.

This method has the characteristics of strong selectivity, good anti-interference ability, and fast response. Compared with traditional laboratory colorimetric methods, it requires no sampling or reagent consumption and truly realizes online continuous monitoring. It is especially suitable for automated water treatment systems that require real-time data.

YEX-COL-408-S Online Color Sensor Technical Specifications

The sensor also has a temperature measurement function and supports automatic compensation to ensure consistency of measurement data under different temperature conditions.

YEX-COL-408-S Online Color Sensor Typical Application Scenarios

The YEX-COL-408-S online color sensor is widely used in the following key areas:

1. Municipal Drinking Water Treatment
          Real-time monitoring of color at water plant inlet, sedimentation tank effluent, post-filtration, and finished water to ensure that sensory indicators of water supply comply with national drinking water standards. Early detection of seasonal organic pollution or secondary pollution in the pipe network to guide process adjustments (such as activated carbon dosing and oxidation treatment).

2. Wastewater Treatment Plant Effluent Monitoring
          Monitoring color and turbidity at secondary treatment effluent, advanced treatment section, and total discharge outlet to verify organic matter removal effect and final effluent quality, meeting environmental protection discharge standard requirements.

3. Industrial Wastewater Discharge Control
          Suitable for chemical, printing and dyeing, pharmaceutical, food processing, papermaking and other industries. Wastewater from these industries often contains colored organic matter. The sensor can be installed at workshop treatment facilities or total discharge outlets to help enterprises monitor treatment effects in real time and avoid environmental penalties due to excessive color.

4. River, Lake and Surface Water Ecological Environment Monitoring
          Environmental monitoring stations can use this sensor to build water quality monitoring networks, track changes in natural water color, evaluate the impact of agricultural runoff, industrial discharge or algal activity on aquatic ecology, and provide data support for comprehensive water body management.

5. Smart Water Management and Online Monitoring Platforms
          Seamlessly integrate with IoT platforms or SCADA systems via Modbus protocol to achieve remote real-time data collection, trend analysis, over-limit alarms, and linkage control, supporting unmanned intelligent water environment management.

Whether in fixed monitoring stations, mobile monitoring vehicles, or automatic river monitoring sections, the YEX-COL-408-S can be quickly deployed to significantly improve the timeliness and accuracy of water quality monitoring.

YEX-COL-408-S Online Color Sensor Installation and Electrical Connection

Installation Guide:

The YEX-COL-408-S adopts submersible installation. Please note the following during installation:

• Place the sensor horizontally and fix it firmly, with the measurement area facing the water flow direction;

• The depth from the water surface does not exceed 2 meters, and ensure it is still submerged more than 30cm at the lowest water level;

• Avoid the sensor hitting walls or other facilities due to water flow; additional fixing is required in fast-flowing areas;

• Choose a location with steady water flow and no large amounts of air bubbles for installation;

• It is recommended to add a protective sleeve outside the cable to enhance long-term durability.

Electrical Connection:

The sensor is equipped with a 5-core shielded cable, with the following wire sequence definition:

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

• Black wire — Ground (GND)

• Blue wire — 485A

• White wire — 485B

• Yellow wire — Current output (optional, can be left floating if not used)

Before powering on, carefully check the wiring sequence. All wiring points must be properly waterproofed, especially in seawater or corrosive environments. The cable should have good corrosion resistance. Waterproof junction boxes or professional waterproof tape are recommended for protection.

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

Maintenance and Care Guide

The YEX-COL-408-S design emphasizes low-maintenance characteristics, but regular inspection and maintenance are still the key to ensuring long-term accurate measurement.

Maintenance Schedule Recommendations:

• Regularly clean the sensor outer surface and measurement window;

• Check the working status of the cleaning brush;

• Perform two-point calibration according to regulatory requirements or actual water quality conditions;

• After 18 months of continuous use, it is recommended to return to the factory for inspection, maintenance of the self-cleaning brush, and replacement of the dynamic sealing device.

Daily Maintenance Methods:

• Rinse the sensor outer surface with tap water; for stubborn dirt, gently wipe with a soft cloth dipped in a small amount of household detergent;

• Check whether the cable is loose to avoid breakage caused by tension;

• Regularly observe the cleanliness of the measurement window and whether the cleaning brush is working normally. Handle any damage promptly.

Precautions:

• Avoid prolonged exposure of the sensor to direct sunlight;

• Do not touch optical components directly with hands;

• Ensure no air bubbles are attached to the sensor surface during measurement and calibration;

• It is strictly prohibited to apply mechanical stress, pressure, or scratches to the sensor;

• There are no user-serviceable parts inside the sensor. If any problem occurs, please contact professional technical support.

FAQ

Q1. Does the YEX-COL-408-S support use in seawater environments?

Yes. The sensor adopts 316L stainless steel housing and IP68 protection rating, with good corrosion resistance. It can be used for estuary, nearshore, or seawater-related monitoring. However, it is recommended to strengthen cable waterproofing and perform regular cleaning.

Q2. Can the self-cleaning brush completely replace manual cleaning?

The cleaning brush can effectively prevent biofouling and dirt accumulation, significantly reducing the frequency of manual intervention. However, in highly polluted water bodies, it is still recommended to conduct regular visual inspections and assist with manual window cleaning to maintain optimal measurement accuracy.

Q3. How does the sensor compensate for turbidity interference on color measurement?

The sensor adopts a dual-wavelength design. One main measurement light is used for color, and one reference light monitors turbidity influence. Real-time compensation is performed through built-in algorithms, which can significantly reduce interference from suspended particles and ensure accurate color data.

Q4. Does the range meet most water quality monitoring needs?

Yes. The color range is 0～500 Hazen and turbidity range is 0～200 NTU, covering most application scenarios for drinking water sources, wastewater treatment effluents, industrial wastewater, and natural water bodies.

Q5. How to integrate with existing automation control systems?

The standard configuration RS-485 Modbus/RTU protocol is compatible with the vast majority of PLC, DCS, and IoT gateways. Optional 4-20mA output is also available for easy integration with traditional analog systems.

Q6. Is the calibration operation complicated?

The operation is simple, requiring only two-point calibration (zero point and slope). It can be completed using standard solutions according to the instruction manual, usually within 10-15 minutes.

Q7. What could cause abnormal fluctuations in measurement values?

Common causes include contamination on the measurement window, abnormal cleaning brush function, or air bubble interference. It is recommended to first clean the window surface and check the cleaning brush status. If the problem persists, please contact technical support.

Q8. What is the product warranty period and after-sales support?

Yexsensor provides a one-year warranty from the date of sale (excluding improper use). If any usage problems occur, our technical team will provide quick response, including remote guidance, on-site support, or factory repair services.

Why Choose Yexsensor?

Yexsensor focuses on the research, development, production, and service of online water quality monitoring sensors, always taking “professional, reliable, and easy to use” as the core philosophy. The YEX-COL-408-S has undergone strict 72-hour aging tests, stability tests, and environmental simulation tests to ensure that every sensor meets high-quality standards before leaving the factory.

We not only provide high-quality hardware products but also are committed to creating complete monitoring solutions for customers. From product selection, technical consultation, installation and commissioning, to later maintenance and data application, the Yexsensor team provides professional support throughout the process to help users efficiently build intelligent water quality monitoring systems.

Take action now:
       If you need an online color sensor with stable performance, simple maintenance, and reliable data, the YEX-COL-408-S will be your high-quality choice. Welcome to contact the Yexsensor sales or technical team to obtain detailed quotations, customized solutions, or product demonstrations. We look forward to working with you to jointly protect clear water quality and a good water environment!