Patent ID: 6842705
Filing Date: 2005-01-11
Classification: G01F,G01N

Abstract:
1. A gas flow measuring device comprising: a gas component adjustor adding target gas, composed of specific gas component contained in measuring object gas or gas differing from the specific gas component to the measuring object gas, or extracting the target gas from the measuring object gas; a first gas concentration detector detecting a concentration of the specific gas component of the measuring object gas prevailing upstream of the gas component adjustor or setting the concentration at a predetermined level; a second gas concentration detector detecting a concentration of the specific gas component of the measuring object gas prevailing downstream of the gas component adjustor; and a gas flow rate calculator calculating at least one of the flow rate of the measuring object gas and the flow rate of the specific gas component on the basis of the concentration of the specific gas component that is detected or set by the first gas concentration detector and the concentration of the specific gas component detected by the second gas concentration detector, and the amount of the target gas added to or extracted from the measuring object gas by the gas component adjustor.