The Thelma Biotel conductivity sensor is located on the face of the transmitter, and the measurements are taken through the four electrodes for wide measuring ranges. The sensor transmitter should be attached externally to a fish, other species, or object to be in direct contact with the water.


  • Available in transmitter sizes 9, 13 and 16
  • Operational lifetime 3+ months


  • Ground – vs surface water
  • Water quality
  • Mining runoff
  • Freshwater use