Improvements in or relating to flexible light guides

Abstract

Abstract 1,042,281. Optical apparatus. RANK ORGANISATION Ltd. Feb. 24, 1965 [Feb. 7, 1964, No. 5200/64. Heading G2J. An instrument for inspecting inaccessible areas comprises an ultra-violet source 16 illuminating the ends of an outer set of hollow quartz glass fibres 12, which are better for transmitting ultra-violet light, and an inner set of optical glass fibres 11, which are better for transmitting visible light, so that when inspecting the inner wall of a tube 19, Fig. 2, (not shown), after supplying oil, which acts as a carrier for ferrous particles coated with a fluorescent dye, to the inner wall of the tube and applying, a magnetic field, by a device 20 outside the tube so that the ferrous particles accumulate over faults in the pipe, the ultra-violet light causes the dye to fluoresce and this is observed through objective system 13, fibres 11 and eyepiece 21. The fibres 11 are in correspondence at each end but fibres 12 may be randomly arranged so that there is no tendency for the source 16 to form an image of its filament at the area under inspection.

Inventors

• 👤 Robert Bentley
• 👤 William Henry Palmer Meredith

Bibliographic Details