Liq. filled optical conductor tube - has plastic construction with each end plugged internally and fitted with outer thin-walled sleeve so plugs do not slide out

摘要

Liq.-filled optical conductor is made of a flexible plastic tube closed off at each end by a transparent cylinder. Outer dia. of the cylinder is larger than the inner dia. of the tube and is itself filled with a transparent liq.. At least one end of the main tube near the internal plug has an outer sleeve which is made of a plastic material and is more rigid than the main tube. This sleeve also has a circular cross-section and just fits over the main tube so as to slide along it. Sleeve has a low absorption of radiation within the visible range and has a small wall thickness compared with its inner dia, and is shorter than the main tube. Main tube is pref. made of a copolymer of vinylidene fluoride units and of units of at least one other monomer contg. F or perfluorethylenepropylene. Sleeve is pref. made of PVDF or tetrafluorethylene. ADVANTAGE - Structure has a safe fit between the end plugs and the main tube (i.e. the plugs are not liable to slide out if e.g. the conductor is heated).