Fiber-Optic System Would Detect Leaking Liquid H2

Proposed instrument based on optical time-domain reflectometry measures both locations and sizes of leaks in tanks and plumbing storing and transferring liquid hydrogen. Conceived for use in detecting leaks of hydrogen from propulsion system of Space Shuttle, concept applicable to detection of flammable and/or poisonous fumes in chemical-processing plants, fuel-distributing equipment, and other terrestrial applications.