Aqueous chemical leak detection cable

Abstract

Disclosed are aqueous chemical leak detection cables that provide protection to sensor wires by using a conductive polymer coating that is resistant to corrosion by aqueous chemicals. In addition, non-conductive, liquid pervious layers may surround one or more of the sensor wires to assist in preventing false detection of a aqueous chemical leak as a result of various non-liquid contaminants. The non-conductive, liquid pervious layer may comprise braided, non-hygroscopic, non-conductive fibers, or a continuous, non-conductive pervious coating.

1 . A method of making an aqueous chemical leak detection cable for sensing aqueous chemicals comprising:
 obtaining a base member that is made from non-conductive polymer that is resistant to corrosion by said aqueous chemicals, said base member having two insulated lobes that are joined together to form two interstices on opposite sides of said insulated conductors, said base member having at least one conductor wire in at least one lobe of said base member;   placing sensor cables in each of said two interstices that have a conductive polymer coating that is resistant to corrosion by said aqueous chemicals, said sensor cables having a sensor wire disposed in each of said sensor cables that is protected from said aqueous chemicals by said conductive polymer coating that is resistant to corrosion by said aqueous chemicals;   twisting said base member to alternately expose said sensor cables along a length of said aqueous chemical leak detection cable so that said aqueous chemical leak detection cable is capable of detecting the presence of said aqueous chemicals on a surface when said aqueous chemicals contact said sensor cables and create a conductive path between said sensor cables resulting in said conductive polymer coating on said sensor cables creating a conductive path to said sensor wires.   
     
     
         2 . The method of  claim 1  wherein said process of obtaining a base member further comprises:
 obtaining a base member that has at least one conductive wire in each of said two lobes. 
 
     
     
         3 . The method of  claim 1  wherein the process of obtaining a base member further comprises:
 obtaining a base member that has more than one conductive wire in each of said two lobes. 
 
     
     
         4 . The method of  claim 1  wherein said process of placing sensor cables in each of said two interstices further comprises:
 placing sensor cables in at least one of said two interstices that have a non-conductive, aqueous chemical pervious layer surrounding said sensor cables that assists in preventing false readings from non-liquid contaminants. 
 
     
     
         5 . The method of  claim 4  wherein said process of placing sensor cables in at least one of said two interstices comprises:
 placing sensor cables in at least one of said two interstices that have braided, non-conductive, non-hygroscopic fibers surrounding at outer surface of at least one of said sensor cables that allows aqueous chemical liquids to pass through openings between said fibers while preventing non-liquid substances from contacting said conductive polymer coating on said sensor cables. 
 
     
     
         6 . The method of  claim 4  wherein said process of placing sensor cables in at least one of said two interstices comprises:
 placing sensor cables in at least one of said two interstices that has a continuous, non-braided, non-conductive, porous coating that surrounds an outer surface of said conductive polymer coating of at least one of said sensor cables and that is resistant to corrosion by said aqueous chemicals, and that allows aqueous chemical liquids to pass through openings in said porous coating while preventing non-liquid substances from contacting said conductive polymer coating on said sensor cables. 
 
     
     
         7 . The method of  claim 4  wherein said process of placing sensor cables in at least one of said two interstices comprises placing sensor cables that are surrounded by non-conductive, non-hygroscopic fibers that comprise poly-meta-phenylene isophthalamide.