Online COD Sensor for Wastewater Monitoring — Modbus RS485
The PRB-COD-RS485-101 measures Chemical Oxygen Demand (COD) continuously in STP discharge, industrial effluent, and process water — using UV absorption, with no chemical reagents, no lab work, and no waiting. Real-time COD over Modbus RS485 RTU.
Why Continuous COD Monitoring?
Batch lab testing tells you what happened yesterday. This sensor tells you what is happening now. Factories and STPs with consent conditions on discharge COD levels can use this to catch exceedances before discharge, not after the regulatory notice arrives.
How It Works — UV Absorption, No Reagents
The sensor uses a dual-wavelength ultraviolet absorption method. Organic matter in water absorbs UV light at a known wavelength. The second wavelength compensates for turbidity interference, giving a more accurate COD reading without chemical oxidation or sample preparation. No reagents. No waste. No consumable chemicals to reorder.
Use Cases
- STP / ETP discharge monitoring — confirm treated water meets pollution control board discharge norms before it leaves the plant
- Industrial wastewater — food processing, textiles, pharmaceuticals, chemical manufacturing
- Inlet / outlet comparison — measure treatment efficiency across each stage of the STP
- Aquaculture — organic load monitoring in fish and prawn farms
Self-Cleaning System
Wastewater sensors foul quickly. This sensor has an integrated automatic self-cleaning wiper that prevents biofouling and slime buildup. Maintenance interval: every 3 months. Self-cleaning system lifespan: 18 months.
Compatible Gateways
- MOFI5A — WiFi Modbus RS485 bridge: push COD readings to cloud over Wi-Fi
- GLCRTU4G — 4G RTU: remote effluent monitoring without local network
- Any third-party Modbus RTU master — PLC, SCADA, environmental monitoring host
Key Specifications
- Measurement principle: Dual-wavelength UV absorption (no reagents)
- Output protocol: Modbus RS485 RTU
- COD range: 0–500 mg/L (equiv. KHP)
- COD accuracy: ±5% FS at 25°C
- Turbidity compensation: 0–200 NTU (built-in, RS485 model)
- Response time: ≤20 seconds
- Power supply: DC 12–30V
- Protection: IP68 electrode
- Cable length: 5 metres standard
- Self-cleaning: Automatic wiper, 18-month system lifespan
- Maintenance interval: Every 3 months