| 摘要 |
PROBLEM TO BE SOLVED: To provide a partial-collecting gas sampling system for exhaust gas measurement capable of diluting partially collected exhaust gas with a diluting gas such as air and controlling the diluting gas with high-speed responsiveness and high precision. SOLUTION: This system comprises a diluting tunnel 4 for diluting the partially collected exhaust gas G, a diluting gas supplying passage 4 connected to the upstream side of the diluting tunnel 4, and gas passages 16, 17 and 24 connected to the downstream side of the diluting tunnel 4 to carry a diluted sample gas S. The diluting gas supplying passage 5 and the gas passages 16, 17 and 24 include differential flowmeters 10 and 26, respectively. A piezo valve 33 is provided on the diluting gas supplying passage 5 so as to be serial to the differential flowmeter 10. The piezo valve 33 is adjusted in opening based on the comparison result of the actual flow rate obtained by the differential flowmeter 10 with a set flow rate. COPYRIGHT: (C)2004,JPO&NCIPI
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