A METHOD AND A SYSTEM FOR DETERMINING A FLOW RESISTANCE ACROSS A PARTICULATE FILTER

摘要

A method of determining a flow resistance across a particulate filter (3) located downstream of an internal combustion engine (1 ) in an exhaust system. The method comprises measuring a first differential pressure (ΔΡ1) across the particulate filter, measuring a second differential pressure (ΔΡ2) downstream of the particulate filter, determining a pressure ratio (ΔΡ1/ΔΡ2) of the first differential pressure and the second differential pressure, and from said pressure ratio, determining a flow resistance across the particulate filter. The second differential pressure is measured across a selective catalytic reduction system (4).