ФОТОАКУСТИЧЕСКИЙ СПОСОБ ИЗМЕРЕНИЯ КОНЦЕНТРАЦИИ НЕУГЛЕВОДОРОДНОГО КОМПОНЕНТА В МЕТАНОСОДЕРЖАЩЕЙ ГАЗОВОЙ СМЕСИ

摘要

The present invention relates to a photoacoustic detection method for measuring concentration of a non-hydrocarbon component of a methane-containing gas mixture. The essence of the method is that the photoacoustic absorption spectrum for the gas mixture is recorded over a suitably chosen wavelength range while the gas mixture is continuously flowing through the measuring apparatus, and then for determining the concentrationof the non-hydrocarbon component the thus obtained spectrum is used in combination with a photoacoustic signal generated by a reference cell (3) filled with a gas having predefined properties. The methane-containing gas mixtureand the non-hydrocarbon component are preferably chosen to be natural gas to be sent out to gas lines and water vapour, respectively. The invention hence allows high-precision detection, even under industrial conditions, of water vapour content present in concentrations as low as about 0.5 ppm in natural gas.