Disaster prevention system of underground space

摘要

PROBLEM TO BE SOLVED: To provide a disaster preventing system in the yard of an underground station, which measures a mist permeability in addition to the concentration of the specific gas, and also rapidly measures the average concentration of the specific gas.;SOLUTION: This diasaster preventing system of the underground space has: a laser irradiation means 30 for irradiating the yard 1 of the underground station with a laser beam having a wavelength in the vicinity of the absorption wavelength due to the specific gas; and a laser detecting means 40 for detecting the emitted laser beam in the yard 1 of the underground station and the concentration of the specific gas in the yard 1 of the underground station is calculated by a laser absorbing method. Further, the mist permeability is calculated by taking the ratio of the emitted incident beam and the detected transmitted beam. When the calculated concentration of the specific gas and the measured value of the mist permeability exceed predetermined values, a central control part raises a fire alarm.;COPYRIGHT: (C)2005,JPO&NCIPI