| 摘要 |
A diffusion path is provided from the exhaust pipe of an internal combustion engine, and a restriction is provided in the diffusion path which permits diffusion of gaseous exhaust therethrough, and which reduces diffusion of particulate exhaust therethrough, reducing contamination and/or poisoning of a downstream sensor. In a lean-burn industrial engine, the exhaust temperature is lower than the operating temperature of a lean-burn oxygen sensor, and the restricted diffusion path concurrently minimizes cooling of the sensor by gaseous exhaust flow thereagainst. The sensor element is in an antechamber in a housing external of the exhaust pipe, and auxiliary heaters in the housing relieve overdriving of the internal heater of the lean-burn oxygen sensor, extending life to meet long interval industrial requirements. |
