GAS DETECTOR USING OPTICAL FIBER

摘要

PURPOSE:To increase the mechanical strength, to improve the accuracy and to expand the gas detection range by forming the sensor and of an optical fiber member which is exposed to inspection gas by using only a core and forming other light propagation parts by providing a core and a clad. CONSTITUTION:The sensor part of the optical fiber member 20 which is exposed to the inspection gas along the longitudinal direction is formed of only the core and other light propagation parts are formed while equipped with the core and clad. A gas cell 30 is arranged in a state incorporating the sensor part 22 of the member 20. The inspection gas is admitted to the gas cell 30 through an entrance pipe 31 and guided out through an exist pipe 32. Laser beam which is propagated in the member 20 is emitted from the right end of the member 20 to reach a germanium photodetector 42 through a V-groove connection part 40 and a quartz dummy optical fiber 41. The photodetector 42 outputs a detection signal corresponding to the intensity of the photodetected laser beam. The detection signal is amplified by an amplifier 50 and inputted to a computer 51.