Patent ID: 7434449

Claim:
An apparatus comprising: an exhaust gas analyzer connecting an SOF measuring system that can measure SOF in exhaust gas and a soot measuring system that can measure soot in the exhaust gas with an exhaust gas line through which a part or all of the exhaust gas discharged from an internal combustion engine flows; wherein the soot measuring system includes a diluter having a sample introducing port connected with (i) a standard gas line through which standard gas whose hydrocarbon concentration is known and which is supplied from a standard gas source flows and (ii) the exhaust gas line, and which can be switched so as to selectively dilute either one of the exhaust gas and the standard gas with diluent gas and extrudes it, a dilution ratio adjusting device that can adjust a dilution ratio of the diluter, and a soot detector that detects soot in the exhaust gas or the standard gas diluted by the diluter; the SOF measuring system can measure hydrocarbon concentration in the standard gas diluted by the diluter with an arrangement that the SOF measuring system can be connected with the diluter; and the dilution ratio of the diluter at this state can be calculated based on the hydrocarbon concentration in the standard gas after dilution when the dilution ratio adjusting device is operated by a certain amount.