F MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01 MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
F01N GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
F01N11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus; , e.g. for catalytic activity