Water Environment Unattended Station: What On-Site Challenges Does the Self-Cleaning Smart COD Sensor Solve - AMT-COD300

Water Environment Unattended Station: What On-Site Challenges Does the Self-Cleaning Smart COD Sensor Solve

Smart type COD(Chemical Oxygen Demand) water quality sensor is an in-situ submersible online intelligent probe, mainly used for real-time monitoring of organic pollution levels in water bodies. It has a built-in microprocessor, compensation algorithms, and communication modules, and can be directly submerged for continuous data collection, making it core equipment for smart water environment monitoring. Mainstream products use the ultraviolet dual-wavelength absorption method (UV254), which differs from the traditional laboratory potassium dichromate chemical method, achieving reagent-free, second-level online monitoring.

1. Working Principle

Based on LambertBeer's Law: aromatic and conjugated organic matter in water has254nm Ultraviolet light has characteristic absorption; the higher the concentration of organic matter, the more ultraviolet light is absorbed.

Dual-beam light source: one path of 254nm ultraviolet light is used to detect organic matter; one path of visible light / UV reference light, specifically corrects turbidity and color interference.

The sensor detects the light intensity after light passes through the water sample, calculates absorbance, and converts it through built-in calibration algorithms to obtain COD value, and can also convert and output BOD、TOCand permanganate index and other indirect parameters.

Integrated temperature sensor for automatic temperature compensation; most are equipped with motorized self-cleaning brushes to remove sludge and biofilm attachments on the measurement window, reducing drift.

Supplementary note: There are also a few intelligent sensors that use small-scale chemical digestion methods, which require reagent consumption, have larger volumes, and higher operation and maintenance costs. The vast majority of intelligent probes on the market use UV optical methods.

Water Environment Unattended Station: What On-Site Challenges Does the Self-Cleaning Smart COD Sensor Solve

2. Main Features

No chemical reagents required, no secondary pollution

No hazardous reagents such as potassium dichromate, concentrated sulfuric acid, or mercury sulfate are used, no toxic waste liquid is produced, significantly reducing consumables and hazardous waste disposal costs.

Second-level rapid measurement,24h Continuous online

A few seconds to30 Outputs a set of data per second, enabling high-frequency continuous monitoring, suitable for capturing sudden water quality changes and overflow pollution peaks; traditional national standard chemical methods require tens of minutes to 2 hours, only intermittent detection possible.

Intelligent compensation and anti-interference

Dual-wavelength algorithm automatically compensates for turbidity, color, temperature, and optical path aging attenuation, adapting to high-turbidity and complex water bodies such as rivers and sewage.

Built-in self-cleaning, low maintenance requirements

Built-in motorized cleaning brush periodically and automatically wipes the optical window, reducing biological fouling and scaling, extending the calibration cycle, suitable for unattended field stations.

Digital intelligent output, easy to connect to IoT

RS485Modbus RTU as standard interface, some support 420mA Analog; built-in chip completes signal processing, data storage, and fault self-diagnosis, and can be directly connected to data acquisition instruments, environmental platforms, buoy monitoring stations, andPLC control systems, supporting remote data viewing.

Hardware protection

IP68 Fully waterproof,316L Stainless Steel / Titanium alloy shell, can be immersed in water for long periods, resistant to sewage corrosion.

Water Environment Unattended Station: What On-Site Challenges Does the Self-Cleaning Smart COD Sensor Solve

3. Typical Technical Parameters (General Reference for UV Type)

Measurement principle: dual-wavelength UV absorption method (254nm + reference light)

COD Range:0100、0500、01000mg/L(multiple ranges optional)

Simultaneous output:CODturbidity, temperature, some output TOC/BOD estimated value

Response time:330s

Communication:RS485 ModbusRTU

Protection rating:IP68

Power supply:1224VDC

Function: automatic turbidity and temperature compensation, motorized self-cleaning

Note: The UV method is an indirect conversion measurement; high salinity and special organic wastewater without UV absorption can cause deviations. Important discharge outlets can be regularly compared and calibrated using national standard chemical methods.

4. Application Scenarios

Municipal sewage: monitoring of wastewater treatment plant influent and effluent, pumping stations, and rainwater and sewage overflow outlets, capturing storm overflow pollution peaks.

Surface water environment: rivers, lakes, reservoirs, micro water stations, buoy stations, grid-based water quality monitoring, pollution warning.

Industrial wastewater: monitoring of chemical, printing and dyeing, and food processing discharge outlets, and circulating cooling water (not applicable to wastewater with completely no UV-absorbing organic matter).

Smart water utilities and environmental IoT: online monitoring platforms, source tracing and investigation, emergency water quality inspections.

5. UV Intelligent COD Sensors vs Traditional potassium dichromate method

Table

Comparison item Intelligent UV COD Sensors Traditional potassium dichromate chemical method

Reagent No reagents required Requires hazardous reagents such as potassium dichromate and mercury sulfate

Detection speed Second-level continuous measurement Tens of minutes to2 hours, intermittent sampling

Secondary pollution No waste liquid Producing toxic waste liquid containing chromium and mercury

安装方式 Direct immersion in-situ measurement Sample intake into the instrument / Laboratory analysis

Operation and maintenance cost Low, mainly periodic calibration High reagent consumption, cumbersome maintenance

Data characteristics Real-time continuous, suitable for early warning High laboratory accuracy, suitable for arbitration and comparison

6. Usage Precautions

The UV method is an indirect measurement; differences in organic matter composition in different water bodies can cause errors, requiring regular comparison and calibration with national standard methods;

High oil and grease, and large amounts of sediment will accelerate contamination of the optical window; the self-cleaning cycle should be reasonably set;

Not suitable for special industrial wastewater with almost no UV-absorbing organic matter;

Installation should avoid bubbles directly attaching to the optical window, ensuring moderate water flow passes over the probe.

If you need, I can help you organize a concise summary suitable for a report, or write key selection points.