FIBER OPTIC LEAK DETECTION SYSTEM. FINAL REPORT, AUGUST 1985-DECEMBER 1986

The objective of the program was to develop a fiber optic based gas pipe leak detection system that can determine, from within an underground pipe, the presence, location, type, and rate of a gas leak. Two fiber optic systems (OTDR and OTDT) along with two fiber modes (multi and single) were tested. To test the optical time domain reflection (OTDR) concept, a short duration light pulse was sent down a fiber optic cable experiencing a localized acoustic disturbance, simulating a gas leak. The disturbance causes a partial reflection of the light pulse to occur. The reflected signal comes back through the beamsplitter and is detected by a photomultiplier tube (PMT). The PMT yields voltage versus time data from which leak characteristics are deciphered. To test optical time domain transmission (OTDT), a continuous helium/neon laser, fiber optic cable, cross-polarizer, and PMT were used. The laser beam was directed down the fiber optic cable. With the crossed polarizers set for null at the detector, a disturbance of the fiber caused light to reach the PMT where voltage time history was recorded.

• Corporate Authors:

  National Technical Systems

  Long Beach, CA  United States 
• Authors:
  • Lieberman, P
  • Nakamura, T
• Publication Date: 1988-8

Media Info

• Pagination: 196 p.

Subject/Index Terms

• TRT Terms: Detectors; Fiber optics; Gas pipelines; Lasers; Leakage
• Old TRIS Terms: Laser applications
• Subject Areas: Bridges and other structures; Design; Highways; Maintenance and Preservation; I61: Equipment and Maintenance Methods;

Filing Info

• Accession Number: 00484686
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: NTS-TR-1524-1, GRI-88/0246
• Files: TRIS
• Created Date: Jun 30 1989 12:00AM