Direct Insertion Detection Technology: This technology involves directly inserting a zirconia probe (measurement cell) into the high-temperature gas flow or atmosphere being tested, achieving in-situ real-time measurement of the oxygen content in the gas. It is particularly suitable for industrial environments with gas temperatures ranging from 700 to 1150°C (with special structural design, it can be extended to 1400°C). Its significant advantage lies in utilizing the high temperature heat carried by the gas itself to maintain the zirconia electrolyte at the required working temperature (usually >650°C), without relying on external additional heaters. The core challenge of this technology is to solve the reliable gas-tight sealing between ceramic materials (zirconia tubes) and metal sheaths in high-temperature environments, as well as designing an electrode system that can operate stably over a long period under high temperatures.