Patent ID: 6882418

Claim:
A device for monitoring the combustion processes occurring in the combustion chamber of an internal combustion engine, with a housing ( 1 ) which can be installed in a wall of the combustion chamber and which has a measuring section which, in the installed state, extends to the combustion chamber, the housing ( 1 ) having a number of drilled holes ( 3 ) which extend alone the longitudinal axis of the housing and in which respective lightguides ( 2 ) are arranged, and a first end, lying at a first end of the drilled hole ( 3 ), of a respective lightguide ( 2 ) receiving light from the interior of the combustion chamber and a second end of the respective lightguide being connected to opto-electronic evaluation devices, characterized in that the drilled holes ( 3 ) have, adjacent to the combustion chamber, an end section ( 3 A) which extends out of the housing ( 1 ) at an angle (α) with respect to the longitudinal axis of the housing ( 1 ) and through an outer face of the measuring section, and characterized in that the first end of the lightguide ( 2 ) has a light entry opening ( 6 ) which is directed onto the interior end of the end section ( 3 A), and a mirrored face ( 5 ) which lies opposite said light entry opening ( 6 ) and reverses the instant light in the direction of the longitudinal axis of the light guide ( 2 ).