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    Picture of Water Quality COD Sensor, 0~200mg/L, 0~500 mg/L Picture of Water Quality COD Sensor, 0~200mg/L, 0~500 mg/L Picture of Water Quality COD Sensor, 0~200mg/L, 0~500 mg/L

    Water Quality COD Sensor, 0~200mg/L, 0~500 mg/L

    1 review(s) | Add your review
    SKU: SUCH-WQS-408
    $1,507.93
    ● 0~200mg/L, 0~500mg/L, 0~1000mg/L ● 0.1 mg/L resolution ● RS485 (Modbus RTU)/ 4-20mA ● Dual-wavelength UV absorption method
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    🚚 Free shipping
    🕒 Delivery date: 6-12 days
    🔁 30-day Returns
    Overview

    High-quality COD sensors are specifically designed for precise detection of organic pollutants in water quality, utilizing the proven UV dual-wavelength absorption principle. Selectable COD ranges include 0~200, 0~500, or 0~2000 mg/L, along with turbidity ranges of 0~200/400/1000 NTU. Accuracy reaches ±5% of reading, maintaining stable performance even in complex water conditions. The water quality sensor provides RS485 and optional 4–20mA outputs for seamless integration into industrial control systems.

    Feature

    COD sensor feature

    • The COD sensor employs reagent-free detection technology, featuring an eco-friendly and maintenance-free design. It enables continuous online monitoring and maintains high measurement accuracy in complex water environments through automatic turbidity compensation.
    • An integrated cleaning brush effectively prevents biofouling. Combined with rapid response and low drift characteristics, it ensures exceptional long-term stability.
    • SUCH water quality COD sensors support multiple output formats including RS485 (Modbus RTU) and 4-20mA. With low power consumption and strong anti-interference capabilities, they integrate seamlessly into various water quality monitoring systems.

    Dimension (unit: mm)

    COD sensor dimension

    Installation Method

    COD sensor installation method

    1. When installing COD sensors, avoid sensor impacts against walls or other hydraulic structures caused by water flow. If the flow is strong, secure the sensor.
    2. Install water quality sensors no deeper than 2 meters below the water surface.
    3. To account for water level fluctuations, submerge the sensor at least 30 cm below the lowest possible water level.
    4. Position the sensor in the water where no bubbles are present.

    Note: It is recommended to install a cable protector around the water quality sensor cable. The COD water quality sensor can be oriented in any direction within the water; however, it is advisable to mount it horizontally and securely, with the measurement area facing the direction of water flow.

    Wiring Diagram

    Function Line Color Specifications
    Power Supply Red Wire Power Supply Positive Terminal (12–24VDC)
    Power Supply Black Wire Power Supply Negative Terminal (GND)
    Communication Blue Wire 485A
    Communication White Wire 485B
    Communication Yellow Wire Current Output (optional—leave floating if not used)
    Specs
    Measurement Principle Dual-wavelength UV absorption method
    Measurement Range COD: 0~200 mg/L; Turbidity: 0~200 NTU
    COD: 0~500 mg/L; Turbidity: 0~400 NTU
    COD: 0~2000 mg/L; Turbidity: 0~1000 NTU
    Resolution 0.1 mg/L
    Accuracy 0~200 mg/L; 0~200 NTU: ±5% of reading
    0~500 mg/L; 0~400 NTU: ±5% of reading
    0~2000 mg/L; 0~1000 NTU: 0~1000: ±10%; 1000~2000: ±5%
    Response Time T90<30s
    Min Detection Limit 0.2 mg/L (0~200 mg/L)
    0.4 mg/L (0~500 mg/L)
    2 mg/L (0~2000 mg/L)
    Calibration Method Two-point calibration
    Cleaning Method Integrated cleaning brush
    Temperature Compensation Automatic temperature compensation (Pt1000)
    Output Method RS485 (Modbus RTU), 4–20 mA (optional)
    Storage Temperature -5 to 65°C
    Operating Conditions 0 to 45°C, ≤0.2 MPa
    Housing Material 316L
    Mounting Method Submersible installation, 3/4 NPT
    Power Consumption 0.4W @ 12V (Operating)
    2W @ 12V (Cleaning)
    Power Supply 12–24V DC
    Protection Rating IP68
    Application

    Water quality sensor for municipal sewage

    Municipal Wastewater

    Water quality sensor for river pollution monitoring

    River Pollution Monitoring

    Water quality sensor for agricultural irrigation

    Agricultural Irrigation

    FAQ
    ❯

    Many organic substances dissolved in water absorb ultraviolet light. Therefore, by measuring the absorption of ultraviolet light at a wavelength of 254nm by these organic substances, the concentration of dissolved organic pollutants in water can be accurately determined. The water quality COD sensor employs dual light sources: one UV light source measures COD concentration in water, while the other reference light source measures water turbidity. Additionally, a specific algorithm compensates for optical path attenuation and can partially eliminate interference from particulate suspended impurities, thereby achieving more stable and reliable measurements.

    ❯

    COD sensors can be used in water bodies containing a certain amount of suspended solids. However, if water turbidity is excessively high, it may cause increased light scattering, leading to elevated measurements. Therefore, in scenarios such as industrial wastewater or combined sewer systems, it is recommended to pair the sensor with a filtration device or an automatic scraping cleaning mechanism to ensure the optical window remains clean. Additionally, certain models incorporate turbidity compensation algorithms to maintain high measurement accuracy in complex water conditions. When selecting equipment, evaluate water quality characteristics and on-site installation constraints.

    ❯

    Common COD sensors support RS485 (Modbus-RTU) digital output, enabling direct connection to PLCs, RTUs, data loggers, and IoT monitoring platforms. Some models also support 4–20 mA analog output, suitable for traditional industrial control systems. During wiring, pay attention to power polarity, communication A/B line correspondence, and ensure stable supply voltage. For outdoor deployment, implement waterproofing, lightning protection, and grounding to ensure long-term reliable system operation.

    1 review(s)
    5.0 1
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    Trevor Haines | 9/17/2026 3:59 AM
    Good COD sensor for continuous monitoring
    Picked this up for a water quality project where I needed to keep an eye on COD without taking samples all the time. I’m using the RS485 connection, and getting it talking to the monitoring system took a bit of trial and error. Once I got the settings right, the readings have been coming through fine. So far, it’s been pretty easy to live with.
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