Physiological Basis of TcPO2: Measures Oxygen MOLECULES (PO2), not saturation!
•Modified Clark electrode
•Gold cathode, silver anode
•When constant polarizing voltage
• applied to cathode, silver in anode
• becomes oxidized by chloride ions to
• form silver chloride
•Reaction generates electrons
•Oxygen molecules at cathode become reduced
•Current is generated in proportion to the number of oxygen molecules in solution