| 摘要 |
PURPOSE:To anticipate the lifetime of medium gas by guiding part of a light generated in a discharge tube, measuring the intensity of a light having a peculiar wavelength by using a plurality of optical filters for passing light colors peculiar for the gas, and calculating an intensity ratio. CONSTITUTION:The spectrum of a light guided to a sensor unit from the spectrum 31 of a light generated between an anode 3 and a cathode 1 in a discharge tube 2 and the spectrum 32 of a light absorbed by the tube and the air becomes as indicated by 33. If the spectrum of the light is incident to the sensor unit, when it passes an optical filter 5 having the transmission rate of the light indicated by 34, it becomes as 35. Accordingly, since the collision probabilities of molecules, electrons, ions are different according to the types of the molecules, ions even in the same concentration as that when the light of different wavelength is guided to a photodetector 4 by replacing the filter 5, an MPU 9 corrects it with a data file 11, and compares as relative concentration to judge whether laser medium gas is proper or not. Thus, the lifetime of the laser medium gas can be anticipated, and the composition and impedance of present laser medium gas can be clearly known. |
