abstract |
A shield for introducing fluid, such as the gas within the exhaust system of an internal combustion engine, to a sensing means such as a zirconium dioxide element of an oxygen concentration sensor. The shield forms a chamber which surrounds the element and contains a particulate trap having a preferred orientation with respect to the main stream flow for intercepting and diverting a portion of fluid from the main stream into a partially closed end of the chamber. The diverted fluid enters the chamber near the tip end of the zirconia element; the closely spaced chamber permits the fluid flow to be generally parallel to the surface of the element and directed from the tip end to the base or housing end of the element. The shield further contains an opening near the base of the element to permit fluid to exit the chamber. |