Abstract: A fluid detection system includes a cable which is capable of being dried easily after coming into contact with the fluid being detected and displays a measurable change in characteristic impedance immediately upon contact with the fluid. The cable comprises an inner conductor and a cylindrical outer conductor disposed in a substantially parallel and coaxial relationship with each other with a dielectric detection layer coaxially disposed between the inner and outer conductors. The outer conductor is of an open braided construction which permits easy passage therethrough of the fluid to be detected. The detection layer comprises a pair of solid dielectric elements stranded around the inner conductor in a double helical configuration and defining an air gap between the two conductors which is adapted to retain the fluid so as to measurably change the characteristic impedance of the cable.

Abstract: An optical fiber cable unit in which an elongated optical fiber is telescoped into an outer jacket such that an annular space is defined between the fiber and the jacket. The space is filled with a polyorganosiloxane "grease" having extremely good thixotropic properties which cause the material to establish a gas-tight seal between the fiber and the jacket while allowing the fiber to float freely within the jacket to avoid elongation of the fiber when tension is applied to the cable.