| 摘要 |
PURPOSE:To measure weak infrared rays by alternatly switching the energies being radiated from a reference ray and the ray to be measured thereby entering the same to the same detector. CONSTITUTION:An infrared ray laser device 1 and a laser device cooling base 3 are alternately scanned by a scanning line M and the respective radiation rays are entered to a detector 7 through a lens L. The reference synchronizing signal to the input terminal of a lock-in amplifier is supplied by an oscillator 10. When the scanning mirror scans the laser device 1, the laser light enters the detector 7 via the lens but at the same time the heat radiation quantity from the laser device itself is absorbed by atmospheric pollution gas. Similarly, when the scanning mirror scans the laser deivce cooling base 3, the radiation light quantity from the cooling base 3 is also absorbed in the atmospheric pollution gas and the quantity of the light after this absorption is entered to the detector 7 via the lens, by which it is converted to an electric signal. This signal is then amplified with an amplifier 8 and is inputted to the lock-in amplifier. |
