Certified Pulmonary Function Technologist (CPFT) Practice Exam

The Clark electrode is specifically designed to measure the partial pressure of oxygen (PO2) in a blood gas analyzer. This type of electrode operates based on the principle of an electrochemical reaction that occurs when oxygen diffuses across a membrane and is reduced at a platinum cathode. The resulting current generated by this reaction is directly proportional to the concentration of oxygen, allowing for the accurate measurement of PO2 in blood samples.

In contrast, the other electrodes mentioned serve different purposes in blood gas analysis. The Beck electrode is not a common reference for measuring oxygen but relates to different analytical functions. The Galvanic cell is another type of electrochemical cell, but it is generally used for continuous monitoring of oxygen rather than for precise measurements like the Clark electrode. Lastly, a reference electrode is used to provide a stable reference potential in various electrochemical measurements but does not directly measure PO2 itself. Thus, the Clark electrode's unique design and function make it the correct choice for analyzing oxygen levels in blood gas analysis.