Yexsensor YEX-BOD-406-S: Industrial Online Fluorescence BOD Sensor

Reagent-free, maintenance-free, high-precision organic matter monitoring solution designed for complex working conditions

In modern water treatment and environmental monitoring projects, traditional five-day biochemical oxygen demand (BOD5) analysis has become difficult to meet the needs of system integrators for automated control due to its long cycle and inability to provide real-time feedback. The Yexsensor YEX-BOD-406-S adopts advanced 275nm ultraviolet excitation fluorescence technology to achieve instantaneous measurement of BOD content by monitoring the fluorescence intensity of organic pollutants after excitation.

Core Selling Points

• Non-contact optical measurement: No expensive chemical reagents required, zero secondary pollution, significantly reducing operation and maintenance Opex.

• Anti-interference and high stability: Built-in 316L stainless steel housing and IP68 encapsulation, optimized for highly corrosive and strongly interfering industrial environments.

• Ultra-simple integration architecture: Standard digital signal output, perfectly compatible with various PLCs, data acquisition instruments and cloud IoT platforms.

Product Overview

The Yexsensor YEX-BOD-406-S BOD sensor is a highly integrated intelligent water quality analysis instrument. It solves the pain points of traditional BOD monitoring equipment such as large size, complex structure and frequent maintenance. This product uses the physical properties of specific wavelength ultraviolet light to excite organic matter in water, converting complex biochemical oxygen demand indicators into stable electrical signals.

For engineering contractors and system integrators, the YEX-BOD-406-S is not just a sensor, but a self-sufficient monitoring node. With extremely low power consumption (<0.2W) and excellent temperature drift control algorithm, it can operate stably for a long time in remote areas or energy-constrained monitoring stations. It is the core hardware support for building digital water affairs and smart environmental protection systems.

Technical Advantages of Industrial Online Fluorescence BOD Sensor

1. Optical physical measurement technology
       Different from traditional electrochemical or chemical titration methods, Yexsensor adopts fluorescence method for monitoring. Through a specific 275nm excitation light source, the sensor can accurately capture the characteristic spectrum of organic matter in water. This physical measurement method has fast response speed (T90 < 30s) and will not cause data drift due to electrode polarization or reagent consumption.

2. Hardware reliability in harsh environments
       The sensor body is made of 316L stainless steel material with strong corrosion resistance, suitable for urban domestic sewage treatment, electroplating wastewater and seawater environments. The IP68 protection level ensures that it can work immersed for a long time at a water depth of 2 meters without leakage risk. In addition, the built-in anti-interference circuit design can effectively filter electromagnetic interference from frequency converters and high-power equipment in industrial sites.

3. Intelligent algorithm and self-cleaning logic
       The sensor has a built-in temperature compensation algorithm that can automatically correct the influence of water temperature fluctuations on fluorescence intensity, ensuring consistency of measurements within the 0~45℃ range. The optional automatic cleaning brush can regularly remove biofilm and attachments on the measurement window surface, reducing the frequency of manual on-site maintenance by more than 80%.

4. Low-cost operation and maintenance and long-life design
       Since no reagents are consumed and there are no wearing parts (except for dynamic seal inspection every 18 months), the total cost of ownership (TCO) of the YEX-BOD-406-S is extremely low. The RS-485 digital interface directly outputs physical quantities, and data can be transmitted over long distances without an external transmitter.

YEX-BOD-406-S Industrial Online Fluorescence BOD Sensor Technical Specifications

BOD Sensor Application Scenarios

• Municipal sewage treatment plants: Monitor inlet and outlet BOD concentrations, evaluate process treatment efficiency in real time, and optimize aeration volume.

• Industrial wastewater discharge monitoring: 24-hour continuous monitoring of discharge outlets in industries such as papermaking, printing and dyeing, and chemical industry to ensure compliance with discharge standards.

• River and lake monitoring: Used in black and odorous water body remediation projects to track the diffusion dynamics of organic pollutants in real time and provide early warning of water quality deterioration.

• Smart water IoT integration: As a sensing layer device, it is connected to the smart city management system to provide underlying data for environmental capacity assessment.

Wiring & Installation Instructions

To ensure the integrity of signal transmission and the durability of the equipment, please follow the following engineering specifications:

Electrical Wiring

The sensor uses a 5-core shielded cable. Strictly distinguish power supply and signal lines:

• Red wire: Power positive (12~24VDC)

• Black wire: Common ground (GND)

• Blue wire: RS-485 A

• White wire: RS-485 B

• Shield layer: It is recommended to ground at one end to reduce high-frequency interference.

Installation Tips

• Avoid bubbles: The measurement window should be placed in an area with steady water flow and no bubble accumulation. Bubbles will cause scattering interference.

• Fixing bracket: In strong flow velocity environments, stainless steel fixing brackets must be used to prevent the sensor from hitting the pool wall and damaging the optical window.

• Installation depth: It is recommended to be immersed 30cm to 200cm below the water surface.

FAQ

Q1: Does the YEX-BOD-406-S BOD sensor really not require any chemical reagents?

Yes. It is based on optical physical principles for measurement and calculates BOD values by capturing the fluorescence characteristics of organic matter in water. It does not involve potassium dichromate or culture medium required by traditional chemical methods at all. It is a green and economical monitoring method.

Q2: Why is there a difference between the BOD measured by the optical method and the BOD5 measured in the laboratory?

The optical method reflects the instantaneous total amount of organic matter in water that can be excited by ultraviolet light. It has a strong correlation but is not completely equivalent. In specific sites, high-precision mathematical models can be established between sensor readings and laboratory BOD5 indicators through multi-point comparison calibration.

Q3: How often does the sensor need to be calibrated?

In environments with relatively stable water quality, it is recommended to perform a two-point calibration (using tryptophan standard solution) every 3-6 months. If the water quality is extremely harsh, it is recommended to shorten the calibration cycle to ensure accuracy.

Q4: Can this sensor measure COD?

BOD and COD usually have a certain correlation in composition. Although this product is mainly optimized for BOD, in some stable working conditions, its readings can be used as a reference for COD indicators after conversion.

Q5: Can 316L stainless steel material be used in seawater?

316L stainless steel has excellent resistance to salt spray corrosion. However, in long-term extremely high-concentration saltwater environments, it is recommended to regularly check the condition of the housing, or customize a higher-grade titanium alloy housing version.

Q6: How to deal with biofilm attached to the measurement window?

Yexsensor provides an optional automatic cleaning brush version. If not selected, it is necessary to regularly wipe manually with a soft cotton cloth and household detergent. It is strictly prohibited to use strong acids, strong alkalis or hard objects to scrape the optical window.

Q7: Can the cable length be extended by myself if it is not long enough?

Yes, but due to the characteristics of RS-485 communication, it is recommended to use high-shielding signal cables and ensure that the joints are properly waterproofed to IP68 level, otherwise it may cause signal drift or equipment damage.

Q8: Why does the dynamic sealing device need to be replaced every 18 months?

For models with automatic cleaning brushes, the sealing parts at the motor rotating parts will experience mechanical wear after long-term operation. The 18-month factory return maintenance is to prevent water from entering and damaging the internal precision circuits through pressure testing and replacement of sealing rings.

Conclusion & Engineering Support

With its excellent industrial design and optical measurement technology, the Yexsensor YEX-BOD-406-S is becoming the preferred solution for many environmental protection integrators. It not only greatly reduces the later maintenance workload, but also incorporates complex water quality parameters into the enterprise's control system in real time through digital interfaces.

If you are looking for highly reliable monitoring components for sewage treatment plant upgrades or smart river projects, please contact our engineering expert team. We can provide you with detailed Modbus protocol manuals and installation bracket design solutions for specific working conditions.

Click “Consult Now” or leave your engineering requirements, and we will provide you with a customized Yexsensor water quality monitoring white paper.