Raychem Limited

Tyco Thermal Controls LLC

Robert S Wasley

Ray F Stewart

Laurence M Welsh

John G Lahlouh

James P Reed

Peter L Brooks

Larry R Reeder

Mauro Bonomi

Michael Masia

Louis M Frank

Kenneth McCoy

Paul D Hauptly

Thomas W Tolles

Denis I Wales

John Lahlough

James C Holmes

Peter Wijeratne

Neil A Edwards

Paul Hauptly

Lawrence Welsh

Kenneth F Mccoy

A sensor for detecting the presence of an organic liquid. The sensor includes an a elongate substrate having a first and second opposed surface, and a first sensor surface disposed on at least a portion of the first surface of the substrate and a second sensor surface disposed on at least a portion of the second surface of the substrate. The sensor also includes a bridging electrode electrically coupling the first and second sensor surfaces, a first electrode disposed on the first surface of the substrate and electrically coupled to the first sensor surface, and a second electrode disposed the second surface of the substrate and electrically coupled to the second sensor surface.

Sensor for detecting organic liquids

A cable suitable for detecting the presence of corrosive liquids is disclosed. In an embodiment the cable includes two sensing wires wrapped around a core member, at least one of the sensing wires being surrounded by a non-conductive surface layer. In an alternate embodiment the cable includes two sensing wires wrapped around a core member, the sensing wires and core member being encapsulated by a non-conductive surface layer. Preferably, the cable includes insulating wires for detecting the location of a leak. When a corrosive liquid contacts the sensing wires of the cable an electrical connection is created between them.

Sensor cable

Detection of liquid leaks and other changes in variables is disclosed. The event causes two elongate conductors to become electrically connected at a location which is determined by the event, thus creating a system in which the connection point can be located by measuring the potential drop from one end of one of the conductors (called the locating member) to the connection point. The system comprises a balancing component so that its sensitivity is not dependent on the location of the event along an elongate path. A fixed current flows through the connection, so that the result is independent of the resistance of the connection. The locating member can be a continuous resistive wire, coated with a conductive polymer; such a locating member can form part of a sensor cable in which the elongate components of the circuit are in a wrapped configuration. Alternatively the locating member comprises a plurality of discrete resistors. The system is arranged so that only connections within a certain range of resistance will activate the system. The voltage drop is calculated by comparing it to the voltage drop over a resistor of known size. Particular event-sensitive connection means are employed for the detection of hydrocarbons.

Method for detecting and obtaining information about changes in variables

An elongate sensor for detecting and locating presence of a liquid, e.g. water or a hydrocarbon. The sensor includes first and second elongate members which are spaced apart from each other and each of which is a metal conductor covered by a conductive polymer; a third, insulated elongate conductor; and an elongate insulating core. At least one of the elongate members is helically wrapped around the core. Presence of the liquid at any point along the length of the sensor causes the first and second members to be electrically connected at that point, creating a system in which the potential drop down one of the members can be measured and the location of the connection determined.

Method for detecting and obtaining information about changers in

Devices for detecting and obtaining information about an event, for example the presence of a liquid, which comprise (1) a swellable member which swells upon occurrence of the event and (2) a restraining member which, when the swellable member swells, restricts movement of the swellable member and thus causes the impedance of the device to change. In a preferred embodiment the device comprises two elongate conductors helically wrapped around a support core, a swellable, conductive polymer member surrounding the conductors. Occurrence of an event causes the swellable material to swell and form a conductive bridge between the conductors.

Sensors for detecting and locating fluids

Detection of events, e.g. liquid leaks and other changes in varibles. The event causes two conductors to become electrically connected, and thus creating a system in which the connection point can be located by measuring the potential drop from one end of one of the conductors (called the locating member) to the connection point. Preferably a fixed current flows through the connection, so that the result is independent of the resistance of the connection. The locating member can be a continuous resistive wire, preferably coated with a conductive polymer; such a locating member can form part of a sensor cable in which the elongate components of the circuit are in a wrapped configuration, or part of a cable in which the conductors are separated by a member shaped to prevent capillary action of a liquid from connecting the conductors. Alternatively the locating member comprises a plurality of discrete resistors. Preferably the system is arranged so that the sensitivity of the system is not dependent on the location of the fault and/or is such that only connections within a certain range of resistance will activate the system. The voltage drop is preferably calculated by comparing it to the voltage drop over a resistor of known size. Particular event-sensitive connection means are preferably employed for the detection of hydrocarbons and for the detection of acids.

Elongate sensors comprising conductive polymers, and methods and

Devices for detecting and obtaining information about an event

A sensing assembly suitable for detecting both a first event which involves the presence of an electrolyte and a second event which does not involve the presence of an electrolyte, and for distinguishing between them. The assembly comprises a first conductor and a second conductor which is electrically insulated from the first conductor in the absence of both first and second events but becomes electrically connected to the first conductor by either an ionic connection in the presence of a first event or an electronic connection in the presence of a second event. The assembly also comprises a sensing apparatus of determining whether the connection is ionic or electronic. The assembly is useful for detecting leaks of hydrocarbons, e.g. gasoline, and water in storage tanks.

Sensor assembly for detecting multiple events and distinguishing between

An apparatus for detecting the occurrence of an event, e.g. the presence of a liquid leak. The apparatus includes an elongate flexible core consisting of elongate elements which are twisted together. The elongate elements comprise first and second sensing members, which each have an electrically conductive outer surface and are physically separated from one another, and at least two elongate insulating members. These elongate elements are covered by a flexible braid which exerts a compressive force on the core. In one aspect of the invention, the flexible braid undergoes a reversible change in appearance when exposed to electrolyte, indicating the location of a leak.

Detection apparatus

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San Carlos, CA, United States of America

Robert S Wasley