Patent ID: 7295319
Filing Date: 2007-11-13
Classification: G01N,Y10T

Abstract:
1. An atmospheric nitrogen dioxide concentration determining method by a single-wavelength laser induced fluorescence technique, characterized in that it comprises the steps of: sampling a test atmosphere from an ambient atmosphere containing nitrogen dioxide of which a concentration is as low as in the pptv order of magnitude and providing a reference atmosphere from the test atmosphere by removing nitrogen dioxide therefrom; irradiating each of the test atmosphere and the reference atmosphere with a single-wavelength laser light having an energy of exciting a nitrogen dioxide molecule from its ground state measuring intensity of a light emitted from the test atmosphere and intensity of a light emitted from the reference atmosphere; and subtracting the intensity of the light emitted from the reference atmosphere from the intensity of the light emitted from the test atmosphere to determine the concentration of nitrogen dioxide in the test atmosphere which is as low as in the pptv order of magnitude.