The sensor of the EZ01 Oxygen Analyzer is based on the principle of solid-state electrochemical cells (using Oxygen oxygen concentration difference).The sensing element itself is a closed-end tube or disk made from ceramic zirconium oxide stabilized with an oxide of yttrium or calcium .porous platinum coatings on the inside and outside serve as a catalyst and as electrodes.At high temperatures(generally above 1292℉/700℃), oxygen molecules coming in contact with the platinum electrodes near the sensor become ionized.As long as the oxygen partial on either side of the cell are equal,the movement is rabdowm and no net flow of ions occurs.If,however,gases having different oxygen partial pressures are on either side of the cell, a voltage is produced .The magnitude of this voltage is a function of the ratio of the two oxygen partial pressures.If the oxygen partial pressure of one gas is known .the voltage produced by the cell indicates the oxygen content of the other gas. A refetence gas.usually air (20.9% O2),isused for one of the gases.