Abstract: A lead member includes a flat conductor having a top face and a bottom face, and insulation films adhered onto both faces of the conductor at a middle portion of the conductor along a length direction of the conductor. The conductor includes a base material that is copper and a nickel plated layer on the base material. A thickness of the conductor has a value larger than, or equal to 0.05 mm, and smaller than, or equal to 0.2 mm. A width of the conductor has a value larger than, or equal to 2 mm, and smaller than, or equal to 7 mm. A thickness of the nickel plated layer has a value larger than, or equal to 2.5 ?m, and smaller than, or equal to 5.0 ?m.

Abstract: A system for detecting fluid-leak in a pipeline or tank is disclosed, which includes a sensing coaxial cable having an outer conductor divided into a plurality of sections and a continuous inner conductor, the coaxial cable being permeable to oily fluids so that the distributed capacity of the coaxial cable can be changed upon penetration by the fluids. Whether or not the change has occurred may be detected by supplying an oscillator signal to each section of the outer conductor to measure an output from the inner conductor at a low frequency signal operational amplifier.

Abstract: This invention relates to an arrangement for detecting the leakage fault of a pipeline by means of a sensing coaxial cable buried in parallel with the pipeline and divided into sections. When an oily substance such as petroleum leaks upon a portion of the sensing cable, the electric characteristics such as the impedance, or the distributed capacity of the cable will change. This change in the distributed capacity is used to detect a small variation in the cable caused by a small leakage of the oily substance, resulting in detecting the fault in the pipeline.