Abstract: A spectroanalytical system includes induction coupled plasma apparatus for exciting sample material to an atomic state for analysis, a source of transport gas, a sample chamber for receiving a sample to be analyzed, and heating means for vaporizing a sample to be analyzed in the chamber and forming particles of the sample of sufficiently small size to form an aerosol. The sample chamber is connected in a flow path between the source of transport gas and the plasma apparatus. A supplemental chamber surrounds the sample chamber, and gas is flowed to the supplemental chamber at a higher rate than the gas flow to the sample chamber. A flow restriction between the sample and supplemental chambers normally permits flow of gas from the supplemental chamber into the sample chamber but also provides pressure relief upon rapid heating for sample vaporization that is effective to minimize pressure transients in the aerosol stream that depress the output signal of the plasma apparatus.