Online COD Analyzer

online-COD-analyzerCOD (Chemical Oxygen Demand) is the amount of external oxygen required to oxidize all organic matter present in sample water. It is a measure of the quality of water and expressed in terms of mg of Oxygen consumed per liter of sample water (mg/L). The COD analysis using Potassium Dichromate as oxidizer is one of the direct methods for COD measurement of organic matter in water.

COD Limits are set by competent authorities for various effluents permissible for accepting them in Effluent Treatment Plants or for releasing them to the environment.

Uniphos Online COD Analyzer is based on the use of Potassium Dichromate as oxidizer. The sampling, process and measurement are automated to minimize human intervention. Online COD Analyzer comes with precision syringe drive system, tiny digestion unit with PID controller, air pump and blower. It is a microcontroller based menu driven instrument with user friendly operation.

Sample Analysis consist of the following steps

  • Sample intake
  • Chloride removal process
  • Digestion
  • Measurement
  • Cleaning and draining
Salient Features

► COD analysis based on sample oxidation using potassium dichromate
► Measures the chemical oxygen demand by measuring the absorbance 3+ of Cr generated
► Ten times reduction in chemicals used as compared to traditional method
► Ten times reduction in cost of analysis
► Fully automated instrument with precision syringe drive system
► Programmed automatic calibration facility
► Can be co-related as online BOD measurement. (optional)
► Data communication compatible with required SPCB/CPCB norms

Application areas

► Municipal water
► Industrial process water
► Waste / Effluent water
► Ground /Surface water

Block Diagram



Measurement Principle : Absorption of digested sample
Measuring Range: 50-2000 mg/L
Resolution: 1mg/L
Accuracy: < 500 mg/L COD: ± 2% FS > 500 mg/L COD: ± 5% FS
Analysis Time: 50 minutes per sample
Digestion: 180° C
Communication: RS-485/USB/4-20mA
Dimensions (cm) : 400 x 350 x 550 (in mm)
Weight: 20 Kg.
Power Supply: 230V, 50 Hz