| 摘要 |
<p>A Method and an Apparatus for Gas Analysis The present invention relates to a method and an apparatus for determining concentrations of substances in gases. The method operates by electromagnetic irradiation and by measuring the intensity of the rays transmitted, at a wavelength which is characteristic of the substance to be detected, wherein the gas containing the substance is measured at at least two different gas pressure values. In order to overcome the drawbacks of the conventional methods which are carried out with reference gases which have to be produced and supplied expressly, but in order nonetheless to be able to quickly and easily determine the concentration of a substance in a gas with a relatively high degree of accuracy, it is proposed according to the invention that an initial measurement be taken at an initial, basically constant pressure of the gas to be analysed, and for the gas pressure to then be changed, and for a second measurement to be taken at a second constant gas pressure with an otherwise identical measuring arrangement, and from the ratio of, or difference between, the intensities measured when the two measurements are taken, the concentration of the substanceto be detected is ascertained in the gas by computer or using a graph, on the basis of a theoretical connection between the extinction and concentration by volume of that substance.</p> |
