Covering the membrane with distilled water prevents the KCl fill solution from evaporating through the membrane. Go to Top 2. A galvanic electrode produces its own current. The electrode is usually silver and lead with a potassium hydroxide electrolyte. Polarographic electrodes have a silver anode surrounded by a gold cathode.
Power is supplied by the DO meter.
Go to Top 3. Temperature affects DO readings in two ways. First, it changes the permeability of the membrane. As the temperature increases so does the permeability of the membrane. As the temperature decreases the oxygen permeability through the membrane decreases.