Abstract: The invention proposes a measuring-probe arrangement for detecting gases flowing in a gas conduit, especially exhaust gases flowing in an exhaust conduit of internal combustion engines. The measuring-probe arrangement has a measuring element (13) which is surrounded in sealing fashion by a housing (11). The section of the measuring element (13a) located at the measured-gas end of the measuring-probe projects from the housing (11) and is surrounded with a clearance by a protective tube (21) which is fixed by one end section on the housing (11) and has one or more openings (22) for the measured gas. The measuring probe (10) is arranged in such a way in the gas conduit (30) that the gas opening (22) is arranged on that side of the protective tube (21) which faces away from the flow (35) of the measured gas.

Abstract: A system for operating a heating element (114) of a ceramic sensor (112) which is arranged in the exhaust channel (104) of an internal combustion engine (100) and which can be heated by the heating element (114). If the internal combustion engine (100) is in an operating state in which it can be assumed that liquid is present in the exhaust channel (114) of the internal combustion engine (100), the heating element (114) is not activated or is triggered such that the ceramic sensor (112) is operated below a critical temperature (TSeK). Above the critical temperature (TSeK) there is a risk that the ceramic sensor (112) will be damaged due to contact with liquid.