Datasheet

Operating principle

A galvanic dissolved oxygen probe consists of a PTFE membrane, an anode bathed in

an electrolyte and a cathode. Oxygen molecules defuse through the probes membrane

at a constant rate (without the membrane the reaction happens to quickly). Once the

oxygen molecules have crossed the membrane they are reduced at the cathode and

a small voltage is produced. If no oxygen molecules are present, the probe will output

0 mV. As the oxygen increases so does the mV output from the probe. Each probe will

output a different voltage in the presence of oxygen. The only thing that is constant is that

0mV = 0 Oxygen.

Electrolyte

Cathode (Pure silver rod)

Membrane

Anode (Zinc)

Time (sec)

90%

60%

5 10 15 20 25 300

Dissolved Oxygen

Stagnant water

Oxygen being

consumed by probe

20%

One of the drawbacks from using a galvanic

probe is that it consumes a VERY small amount

of the oxygen it reads. Therefore, a small amount

of water movement is necessary to take accurate

readings. Approximately 60 ml/min.