Patent ID: 9410872
Filing Date: 2016-08-09
CPC Classification: F01N,G01F,G01M,G01N

Claim Text:
1. An exhaust gas flowmeter used for an exhaust gas dilution system that is provided with a main flow path through which exhaust gas emitted from an internal combustion engine flows, and a diluent gas flow path through which diluent gas for diluting the exhaust gas flows, the diluent gas flow path meeting the main flow path, the exhaust gas flowmeter comprising: a first sampling line for, from an upstream side of a meeting point between the main flow path and the diluent gas flow path in the main flow path, sampling raw exhaust gas that is the exhaust gas before dilution; a first concentration measuring part that is provided in the first sampling line to measure concentration of a predetermined target component contained in the raw exhaust gas; a second sampling line for, from a downstream side of the meeting point in the main flow path, sampling diluted exhaust gas that is the exhaust gas after dilution; a second concentration measuring part that is provided in the second sampling line to measure concentration of the predetermined target component contained in the diluted exhaust gas; and an arithmetic unit that, with use of first measured concentration of the predetermined target component obtained by the first concentration measuring part, second measured concentration of the predetermined target component obtained by the second concentration measuring part, and a diluted exhaust gas flow rate that is a flow rate of the diluted exhaust gas, calculates a raw exhaust gas flow rate that is a flow rate of the raw exhaust gas, wherein in a state where the first sampling line and the first concentration measuring part are heated, the first concentration measuring part measures the concentration of the predetermined target component contained in the raw exhaust gas.