| 摘要 |
PROBLEM TO BE SOLVED: To precisely evaluate noise outside a vehicle while removing surely exhaust gas generated in a measuring chamber. SOLUTION: An exhaust gas control device 32 for sucking the exhaust gas discharged from a muffler 4 of a testing vehicle 2 to be discharged to the outside is provided in a position, that is a rear position of the testing vehicle, deviated from an area connecting microphones 8d-8g provided in a vehicular rear side of the testing vehicle and the muffler. The exhaust gas control device is provided with a suction exhaust part, and a trumpet-shaped hood 38 connected to the suction exhaust part and opened toward the muffler. The suction exhaust part has a suction flow rate exceeding the maximum value of an exhaust gas flow rate discharged from the muffler. A diameter of an opening, and a distance from an exhaust delivery port to a tip part of the opening are properly changed in response to variation of a flow rate of the exhaust gas ejected from the exhaust delivery port of the muffler. COPYRIGHT: (C)2005,JPO&NCIPI
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