Particulate matter concentration measuring apparatus

摘要

A particulate matter concentration measuring apparatus, which measures a particulate matter concentration in exhaust gas flowing in an exhaust line of a diesel engine, includes an exhaust gas extraction line that is branched from the exhaust line and has a flow passage cross-sectional area smaller than a flow passage cross-sectional area of the exhaust line; a particulate matter detection filter that is provided in the exhaust gas extraction line and catches particulate matter; a heating unit that heats the caught particulate matter; and a differential pressure detection unit that detects a differential pressure generated between an inlet and an outlet of the particulate matter detection filter. The heating unit is arranged to apply 50% or more of a calorific value for heating the particulate matter to an area making up 30% of the particulate matter detection filter on an upstream side of an exhaust gas flow.