Measuring sensor for determining the oxygen content in gases

Claim 1

A combination of a measuring sensor and protector for determining an oxygen content in gases having solid particles, in particular for exhaust gases of internal combustion engines, the combination comprising: a measuring sensor including a housing with an open end and an elongated measuring element having a first portion bounded by the housing and a second portion extending through the open end, the second portion having an element end spaced furthest from the open end of the housing; said protector positioned and arranged for protecting the second portion of the measuring element from the gas to be determined for oxygen content and including an elongated cup-like protective pipe with a pipe end engaging the open end of the housing, said pipe forming a chamber, said chamber accomdating said second portion, said pipe having a longitudinal axis and a bottom portion arranged furthest away from said pipe end; and said protector including means for guiding the gas through said chamber and including an inlet opening in said pipe communicating with said chamber at said bottom portion, at least one outlet opening in said pipe communicating with said chamber and spaced away from said bottom portion, and deflection means extending inward from said pipe at an acute angle relative to said longitudinal axis of said pipe and away from said bottom portion so that when the gas flows longitudinally through said chamber from said inlet opening, the gas is deflected by said deflection means to flow around said deflection means to said at least one outlet opening, said bottom portion having a convex shape and having a boss-like bulging portion projecting outward and forming said inlet opening so as to reduce contamination of the measuring element by solid particles by preventing solid particles in gases from entering said chamber.