Raychem Limited

Michael A Lutz

Abdul M Tayeb

Howard B Kroymann

Edward H Softky

The invention is the use of a solid conductive polymeric composition, which displays a massive resistance increase upon exposure to an external fault condition, as one plate of a capacitor for a continuous sense and locate device. This resistance increase of the conductive polymeric composition (CPC) decreases the capacitance of the capacitor so as to provide an indication of the fault and its location.

Continuous sense and locate device

An apparatus for monitoring the value of one or more physical parameters, the apparatus including a plurality of physical monitoring modules, master electronics, and structure for interconnecting each of the modules and the master electronics. Each module includes a logic section and a transducer section. The logic section receives a logic signal and responds by activating the transducer. The logic signal is passed to the next module according to a clock pulse which is generated from the master electronics. The transducer senses a physical parameter. When activated, the transducer responds to the physical parameter with an electrical signal and communicates the electrical signal to the master electronics which utilizes the electrical signal for monitoring purposes.

Cascade monitoring apparatus

A temperature excursion sensor and locator consisting of a temperature sensitive cable which includes two electrical conductors separated by a dielectric member to form a linear strip capacitor wherein at least one of the conductors is comprised of a number of thermostatic devices connected serially. An over or under temperature excursion is sensed and located by the cable when it is connected from either end to control electronics by measuring the capacitance of the cable. Under normal conditions, all of the thermostatic devices are electrically conducting and the control electronics measures the full capacitance. Upon occurrence of a temperature excursion, one or more thermostatic devices become non-conductive and the resulting measured capacitance is proportionately reduced. Presence of the temperature excursion is sensed and its location indicated by the control electronics which compares the full cable capacitance to the reduced capacitance, the ratio of said capacitances determining the location of the temperature excursion.

Temperature excursion sensing and locating apparatus

The invention is an over-temperature sensor and locator utilizing a temperature sensitive cable comprising (1) an electrical conductor, (2) a dielectric, and (3) a solid, conductive polymeric, positive temperature coefficient of resistance composition. An over-temperature condition at any point along the cable is detected by a drop in the capacitance of the cable, as measured from one end of the cable. The location of the over-temperature point on the cable is determined by comparing the reduced capacitance from the control end to the over-temperature point with the capacitance of the full cable length.

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San Carlos, CA, United States of America

Michael A Lutz