ISSN:
1432-0649
Keywords:
42.80
;
07.65
;
82.80
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract This paper reports and discusses, for the first time, the all-optical remote monitoring method for spilled dispersals or leakages in air of city gas through the nearinfrared absorption of CH4 gaseous molecules as one of its major constituents, using a very low-loss optical fiber network and compact absorption cells in conjunction with high radiant InGaAsP light-emitting diodes (LEDs). For this new application, the near-infrared absorption spectra of city gas (Sendai, Japan) were measured and analyzed to find a relatively strong absorption due to thev 2 + 2v 3 combination band of CH4 molecules around the wavelength region of 1.33 μm. By using a 2-km long very low-loss silica optical fiber link, this fully optical system was demonstrated to be feasible, safe and capble of achieving reproducibly the detection sensitivity of nearly 1 Torr of CH4 gas in air, i.e., 2.6% of the lower explosion limit of CH4 density in air. This result supports the conclusion that the alloptical remote sensing system incorporating very low-loss optical fiber networks and LEDs or laser diodes (LDs) in the near-infrared region can be extensively utilized for the real-time detection and surveillance of spills or leakages of the city gas or any other gas mixtures as well as various combustible, explosive, dangerous, and toxic gases not onlyin industrial and mining complexes but also in urban and residential areas.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00692820
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