Patent ID: 9518969
Filing Date: 2016-12-13
CPC Classification: F01N,G01N,Y02A

Claim Text:
1. A gas analysis apparatus comprising: a mixed gas sampling pipe that does not provide a flow path to a selective catalytic reduction (SCR) catalyst and that, from a sampling port formed on one end side inside an exhaust gas pipe, samples mixed gas that is a mixture of exhaust gas emitted from an internal combustion engine and a misty urea aqueous solution; a decomposition reaction controlling mechanism that controls a decomposition reaction of urea or isocyanic acid in the mixed gas sampling pipe; a produced substance measuring mechanism that is provided on an other end side of the mixed gas sampling pipe downstream from the decomposition reaction controlling mechanism and measures a value related to an amount of a substance produced from the urea or the isocyanic acid in the urea aqueous solution; a calculation part configured to calculate an amount of the urea contained in the mixed gas, on a basis of a measured value measured by the produced substance measuring mechanism; and a filter, including fibers, that is provided between the sampling port and the produced substance measuring mechanism in the mixed gas sampling pipe to collect the urea in a solid state or in a state of being dissolved in water in the mixed gas, wherein the decomposition reaction controlling mechanism is configured to control a temperature of the filter or a voltage applied to the filter.