Abstract: An analyzer compensates for gas flow perturbations by providing a makeup flow of carrier gas to maintain the pressure and/or flow rate of analyte and inert gas through a detector constant such that a accurate determination of a low concentration of an analyte in the presence of a high concentration of a second analyte can be accurately determined. In one embodiment, a carrier gas is introduced through a valve responsive to the detected pressure in the gas flow stream between a scrubber and a subsequent detector for maintaining the pressure constant during an analysis. In another embodiment of the invention, a flow transducer is positioned in the gas flow path between the scrubber and detector and coupled to a flow control valve coupled to introduce carrier gas as a function of detected gas flow such that the flow rate of gas into the detector is maintained constant.