Oxygen Electrode Discs
Introduction
The Hansatech Instruments oxygen electrode disc is a specialised form of electrochemical cell known as a Clark type polarographic sensor which comprises a resin bonded central platinum cathode and a concentric silver anode. During measurements, the anode and cathode are linked by a 50% saturated potassium chloride (KCl) electrolyte solution. The electrolyte forms a bridge between the 2 electrode elements via the aid of a fine paper wick which is applied to the electrode disc during the preparation process along with a fine layer of PTFE membrane which is selectively permeable to oxygen molecules. Both are held in place with an O-ring.
Once preparation of the electrode is complete, the disc assembly is mounted into the base of an electrode chamber with the membrane covered dome section of the disc forming the floor of the reaction vessel. The electrode disc is connected to a control unit which supplies a polarising voltage of 700mV. In the presence of oxygen, a polarised disc generates a small current which is directly proportional to the concentration of oxygen in the reaction vessel above the cathode. This current is converted to a voltage, conditioned and digitised with high resolution before display by the electrode control unit.
S1 Electrode Disc
The S1 electrode was designed in the early 1970's during a collaborative project between Prof. David Walker, Prof. Tom Delieu and Hansatech Instruments. The first S1 went on sale in 1974 and has remained largely unchanged in over 30 years. A range of complementary instruments have been developed over the years in order to meet the needs of emerging trends in the scientific world. Modern oxygen measurement systems incorporate the S1 electrode providing sensitive and reliable tools for a vast range of applications from the demonstration of oxygen evolution from photosynthetic organisms to the analysis of mitochondrial respiration rates.
S1/MINI Electrode Disc
The S1/MINI oxygen electrode disc is designed specifically for use with the Oxytherm electrode control unit. The operational specifications for the disc are identical to those of the S1. The only difference is the smaller size of the electrode body.