초록 ▼

Fiber optic waveguides exhibiting a blackout phenomenon can be used for temperature sensing. A temperature sensing waveguide can be used in such applications as maintaining a material within a selected temperature range, freeze protection viscosity control of liquids in pipelines, leak detection of

Fiber optic waveguides exhibiting a blackout phenomenon can be used for temperature sensing. A temperature sensing waveguide can be used in such applications as maintaining a material within a selected temperature range, freeze protection viscosity control of liquids in pipelines, leak detection of cryogenic fluids, fire detection, application of heat-recoverable materials, battery charging, and fluid level detection. Novel waveguides exhibiting blackout at selected temperatures for use in these applications are described.

대표청구항 ▼

Apparatus for maintaining a material within a temperature range of from T1 to T2, T1 being less than T2, and T2 being less than 200°C., the apparatus comprising: (a) a waveguide, at least part of the waveguide being in thermal communication with the material so that the temperature of said part of t

Apparatus for maintaining a material within a temperature range of from T1 to T2, T1 being less than T2, and T2 being less than 200°C., the apparatus comprising: (a) a waveguide, at least part of the waveguide being in thermal communication with the material so that the temperature of said part of the waveguide is responsive to the temperature of the material, the waveguide comprising a core and cladding disposed on and around the exterior surface of the core, said part of the waveguide exhibiting blackout at a blackout temperature TB, TB being about equal to T2; (b) means for directing light at an end of the waveguide; (c) means for monitoring the intensity of light transmitted by said part of the waveguide; and (d) means for cooling the material when the means for monitoring detects a substantial change in the intensity of the light transmitted by said part of the waveguide.