METHOD OF SPECTROCHEMICAL ANALYSIS OF IMPURITY IN GAS

摘要

The present invention provides an absorption spectrographic analysis method which uses frequency modulated semiconductor laser light. In this method an absorption spectrum is measured by setting a current value B at which saturation of variation in laser emitting power which accompanies increases in injection current for a semiconductor laser as a lower limit current value for the injection current to the semiconductor laser-emitting element; setting a current value C at which variation in wavelength transition which accompanies increases in injection current initially becomes minimal as an upper limit current value for the injection current to the semiconductor laser-emitting element; and using laser light which oscillates at an injection current region between this lower limit current value and this upper limit current value as the semiconductor laser light. According to the method of the present invention, it is possible to measure minute amounts of impurities contained in gases with high sensitivity and accuracy. <IMAGE>