System for measuring amount of particulates exhausted from vehicle engine

Claim 1

In a system for measuring the amount of particulates of dry soot and soluble organic fractions contained in exhaust gas from an internal combustion engine, comprising a dilution tunnel in which the exhaust gas is mixed with and diluted by a large amount of clean air, a blower means for sucking the exhausted gas and the clean air into said tunnel section and discharging the diluted gas therefrom and means for detecting the amount of particulates in the diluted gas, the improvement in which said means for detecting the amount of particulates in the diluted gas comprises first and second arrangements for detecting the amounts of dry soot and soluble organic fraction, respectively, said first arrangement comprising a first sampling pipe for extracting one part of the diluted gas from said dilution tunnel, a first sampling pump for flowing the diluted gas through said first sampling pipe, a first filter for depositing the dry soot on said first filter, a first heating means disposed in the upstream region in said first sampling pipe for heating the diluted gas taken in said first sampling pipe, a first pressure transducer for converting a value of a pressure drop across said first filter to an electrical signal, and a first processor for calculating the amount of dry soot in the exhaust gas in accordance with a differential value of the pressure drop output from said first pressure transducer as a function of time, while said second arrangement comprising a second sampling pipe for extracting another part of the diluted gas from said dilution tunnel, a second sampling pump for flowing the diluted gas through said second sampling pipe, an additional filter of a relatively large size for depositing dry soot on said additional filter, a second heating means disposed in the upstream region in said second sampling pipe for heating the diluted gas taken in said second sampling pipe, a second filter disposed downstream of said additional filter for depositing the soluble organic fraction on said second filter, a second pressure transducer for converting a value of a pressure drop across said second filter to an electrical signal, and a second processor for calculating the amount of soluble organic fraction in the exhaust gas in accordance with a differential value of the pressure drop output from said second pressure transducer as a function of time.