초록 ▼

An oil-level detector is mounted on the outside face of a glass window in the wall of an oil tank. The detector has two fibre-optic cables which extend within a cavity between the detector and the window. The ends of the cables are mounted one above the other, one cable transmitting a beam of light

An oil-level detector is mounted on the outside face of a glass window in the wall of an oil tank. The detector has two fibre-optic cables which extend within a cavity between the detector and the window. The ends of the cables are mounted one above the other, one cable transmitting a beam of light at an angle aa

대표청구항 ▼

A liquid reservoir of the kind having a wall, a window of transparent material mounted in said wall, and a liquid-level detector mounted on said reservoir, the improvement wherein the detector comprises: a mounting assembly shaped to define a cavity facing said window; means sealing said mounting as

A liquid reservoir of the kind having a wall, a window of transparent material mounted in said wall, and a liquid-level detector mounted on said reservoir, the improvement wherein the detector comprises: a mounting assembly shaped to define a cavity facing said window; means sealing said mounting assembly with said window; a transparent liquid or gel in said cavity, said liquid or gel having a refractive index substantially the same as that of said window; transmitting means for transmitting a beam of light through said cavity towards said window at an angle greater than the critical angle of said transparent material with air and less than the critical angle of said transparent material with the liquid in said reservoir, such that said beam of light is refracted into said reservoir when the liquid in the reservoir covers the location at which said beam is incident on the internal face of said window, and is reflected by said internal face when said location is uncovered by the liquid in said reservoir; and receiving means for receiving said beam of light when it is reflected from the internal face of said window, said receiving means providing an output which changes as the level of liquid in said reservoir moves over said location.