MEASURING APPARATUS FOR ATMOSPHERE CONTAMINATING MATERIAL

PURPOSE:To make it possible to perform high performance measurement at a low cost by generating large-scale plasma under the state wherein the internal pressure in a specified cavity container is atmospheric pressure, there is no other gas, and there is only air, and generating light rays corresponding to an element to be measured. CONSTITUTION:In a cavity resonator 61 of a plasma generating part, a microwave sent through a straight waveguide 55 forms a stead state wave in a cylinder tube 62, and the wave is confined. Because of the confining effect, a magnetic field whose magnetic field component H is sufficiently stronger than the magnetic field component Ho of the microwave in the waveguide 55 is formed in a loop shape in approximate symmetry with respect to the axial core line of the tube 62. A powerful electric field E is induced in a doughnut shape with the axial core line as the center. The more powerful electric field is concentrated at the tip part of a metal protruding piece 65 which is a plasma exciting member by the electric field E. The gas (air) in the tube 62 is ionized. The plasma is generated in the vicinity of the tip of the protruding piece 65 under the atmospheric pressure. A fire ball is generated, and the light rays corresponding to the component of the element of the sample is generated.