Total Dissolved Gas Sensor - In-Situ Inc TDG

When water becomes super-saturated with gases it can become lethal to fish. So monitoring the Total Dissolved Gas can be important for effective water quality management.

When the total pressure of all the gases in the water exceeds the ambient atmospheric pressure at the water surface, supersaturation exists. The effect of excessive supersaturation on fish has been well documented, and if supersaturation exceeds the established safe levels, massive fish kills can occur.

Supersaturation can be caused by numerous man made and natural sources:

  • Dam spillways which allow the discharge to plunge deeply into the receiving water
  • Heated discharge of thermo-electric power plants can raise the temperature
    of the receiving water to a point of supersaturation
  • Faulty water pumps used in aquaculture recirculatory systems can
    cause air entrainment if a leak occurs on the suction side of the pump
  • Naturally high levels of nitrogen can be found in well water
  • Algae blooms can cause increased levels of gas in the water Precautions can be taken to keep supersaturation within safe levels, but accurate in-situ gas measurements must be made to determine if remedial action is effective. The TDG Sensor makes this measurement quick and easy 


Research subject: Instrumentation