A dissolved oxygen meter is a scientific device used to measure the amount of gaseous oxygen dissolved in water or other liquids.
How It Works
  • Optical Sensors: Use luminescent light. Oxygen quenches the light; the meter measures this change to find the oxygen level. They need little maintenance and no constant water stirring.
  • Electrochemical Sensors: Use a membrane and an electrolyte solution (polarographic or galvanic). Oxygen passing through the membrane creates an electrical current that the meter reads.
Key Measurements
  • mg/L or ppm: Shows the absolute weight of oxygen per liter of water.
  • % Saturation: Shows the ratio of oxygen relative to the maximum possible amount at that specific temperature and pressure.
  • Temperature: Most meters track temperature simultaneously because water temperature changes how much oxygen it can hold.
Common Uses

  • Aquaculture: Monitoring fish farms to ensure fish have enough oxygen to breathe.
  • Wastewater Treatment: Checking aeration tank efficiency.
  • Environmental Testing: Testing lakes, rivers, and streams for ecological health.