Patent ID: 8220310

Claim:
A gas analyzer comprising: a separation column; a surface acoustic wave device; a surface acoustic wave measuring means; and an analysis means; the separation column being configured so as to pass a sample gas together with a carrier gas through the inside of the column, and having different pass times depending on the kinds of components of the sample gas, the sample gas containing several kinds of components; the surface acoustic wave device comprising: a base material with an annularly continuous annular surface formed of at least a part of a spherical surface; a surface acoustic wave generating means capable of generating a surface acoustic wave that propagates along the annular surface; and one or more reaction parts provided along the annular surface so as to change attenuation and velocity of the surface acoustic wave propagating along the annular surface generated by the surface acoustic wave generating means, in response to one or more kinds of components of the sample gas; the surface acoustic wave device being arranged so that the sample gas passing through the separation column reacts with the reaction parts; the surface acoustic wave measuring means measures amplitude determined by the attenuation of the surface acoustic wave propagating along the annular surface generated by the surface acoustic wave generating means and delay time is determined by the velocity of the surface acoustic wave; and the analysis means analyzing the components of the sample gas based on the amplitude and delay time measured by the surface acoustic wave measuring means, the analysis means determining velocity of the surface acoustic wave from the delay time measured by the surface acoustic wave measuring means, determining attenuation at a plurality of different frequencies of the surface acoustic wave from the amplitude measured by the surface acoustic wave measuring means, calculating the partial pressure of each component of the sample gas based on the velocity and the attenuation at each frequency, and solving simultaneous equations containing the velocity and the attenuation and using the partial pressure of each component of the sample gas as a variable.