LONG-TERM CROPS WITH FIBEROPTIC VALIDATORS TO PROMOTE AND SECURITY SYSTEM WITH STRENGTHED IMPACT ON IT

摘要

A composite strip for use in a security system comprises an integrally barbed or serrated carrier strip having a longitudinal groove therein. A fibre-optic filament is disposed in the groove and is held therein by means of an adhesive strip which is applied to the carrier strip so as to overlie the groove. Such a composite strip may provide security against unauthorized crossing of a boundary by directing light into one end of the filament and detecting the light leaving the other end of the filament. An indication is given when the optical intensity of the detected light falls below a predetermined threshold, so as to warn when the fibre-optic filament has been disturbed significantly or cut through.