METHOD AND DEVICE FOR ANALYZING MINUTE IMPURITY IN GAS SAMPLE BY USING DIODE LASER

摘要

PROBLEM TO BE SOLVED: To provide a method by which at least one kind of minute impurity in a gas sample can be analyzed by emitting a light from a semiconductor diode and absorbing the impurity to be detected. ;SOLUTION: A light 2 emitting from a diode 1 is separated into at least two branched lights, and one, measuring light 3, is passed through a gas sample to be analyzed in a muti-passage cell 5 and focused on a light detector 6, while the other, reference light 4, is passed through a reference passage and focused directly on a reference light detector 15 without encountering with the gas sample. The gas sample is at least at a pressure equivalent to the atmospheric pressure, and the modulation including at least one exponential function is introduced in the supply current for the diode 1.;COPYRIGHT: (C)1997,JPO