Primarily utilizes the electrical conductivity of zirconia to measure oxygen concentration in gases. Marathon models typically start with "F" or "MMI," offering a complete range. They are heat-resistant but fragile.

Diameters are available in 22 and 25mm.

Even values are divided into even and uneven, even values are categorized as S, R, K even, N even is without even, two wires are without even, and four wires are with even.

During use, follow the operating instructions, properly connect the probe to the measuring instrument, and calibrate and adjust as needed. Keep the probe dry and clean during operation, and avoid contact with corrosive substances such as strong acids and alkalis.

　　J The year average air temeperature is 14 Celsius degrees, the year average rainfall is 650-700 millimeters.