摘要:
A method for measuring degradation of electrical power system device insulation utilizes a conductive composite sensor. A selected polymeric matrix of the conductive composite provides a sensor resistance response that correlates to degradation of the insulation. The sensor may be embedded in the windings, core or stator of the electrical power system device and wired to a connector on the electrical power system device for interrogation by an ohmmeter.
摘要:
An in-situ method for monitoring the health of a composite component utilizes a condition sensor made of electrically conductive particles dispersed in a polymeric matrix. The sensor is bonded or otherwise formed on the matrix surface of the composite material. Age-related shrinkage of the sensor matrix results in a decrease in the resistivity of the condition sensor. Correlation of measured sensor resistivity with data from aged specimens allows indirect determination of mechanical damage and remaining age of the composite component.
摘要:
An electrical condition monitoring method utilizes measurement of electrical resistivity of a conductive composite degradation sensor to monitor environmentally induced degradation of a polymeric product such as insulated wire and cable. The degradation sensor comprises a polymeric matrix and conductive filler. The polymeric matrix may be a polymer used in the product, or it may be a polymer with degradation properties similar to that of a polymer used in the product. The method comprises a means for communicating the resistivity to a measuring instrument and a means to correlate resistivity of the degradation sensor with environmentally induced degradation of the product.
摘要:
A fault sensing electrical wire (411) utilized one or more sensor strips (407) which provide an impedance change when the wire is subject to an overtemperature condition or mechanical damage of the wire. A control unit (402) measures the impedance of the sensor strips of the fault sensing wire and provides a control signal (405) to initiate an alarm or protective action based on the severity of the condition. The control unit (402) may monitor a number of fault sensing sires simultaneously or in sequence. The apparatus may be used to sense an electrical arc occurring in the insulation of the wire.
摘要:
A multi-ply paper web comprises a base ply of a post-manufactured sheet such as reused old newsprint or reused office waste. An upper and/or lower ply bonded to the base ply covers any printing or contamination of the base ply, thus allowing the resulting web to be reprinted or used for writing or packaging grades. The base ply is not repulped, reducing water and energy usage in the manufacturing process. The upper and lower plies may be wet formed or dry formed. Dry-formed upper and/or lower plies result in a paper product utilizing little or no water in the manufacturing process, and no aqueous effluent. The post-manufactured base ply provides the strength ply. Multiple layers in the base ply or, alternatively, a contrast-reducing process on printed surfaces of the base ply, reduce show through of the final web.
摘要:
An electrical safety device comprises a sensor strip disposed in the insulation of an electrical power cord or other electrical apparatus. The sensor strip is made of a conductive polymer with a positive temperature coefficient of resistivity which increases with temperature. The sensor strip forms a series connected loop connected to an impedance measuring circuit. A relay interrupts current to the conductors of the cord when the impedance of the sensor strip increases due to an overtemperature condition. The sensor strip is positioned between the conductors of the cord and the outside surface of the cord. The position of the sensor strip allows the strip to act as a mechanical damage sensor, opening the series connected loop before an energized conductor is exposed.
摘要:
An environmental degradation sensor for environmentally sensitive products such as food, pharmaceuticals or cosmetic products provides the degraded state and estimated remaining life of the product. The sensor is made of a polymeric matrix and conductive filler. A control agent, selected to adjust a reaction rate of the sensor to environmental conditions, allows correlation of an electrical property of the sensor to a degraded state of the product. The sensor may be integrated with a passive RFID to provide product identification and degradation status wirelessly via reader. The sensor improves product safety, reduces cost of premature product disposal and, combined with RFIDs, improves the security of products through combined product degradation monitoring and tracking.
摘要:
An electrical condition monitoring method utilizes measurement of electrical resistivity of a conductive composite degradation sensor to monitor environmentally induced degradation of a polymeric product such as insulated wire and cable. The degradation sensor comprises a polymeric matrix and conductive filler. The polymeric matrix may be a polymer used in the product, or it may be a polymer with degradation properties similar to that of a polymer used in the product. The method comprises a means for communicating the resistivity to a measuring instrument and a means to correlate resistivity of the degradation sensor with environmentally induced degradation of the product.
摘要:
A fault sensing electrical wire (411) utilizes one or more sensor strips (407) which provide an impedance change when the wire is subject to an overtemperature condition or mechanical damage of the wire. A control unit (402) measures the impedance of the sensor strips of the fault sensing wire and provides a control signal (405) to initiate an alarm or protective action based on the severity of the condition. The control unit (402) may monitor a number of fault sensing wires simultaneously or in sequence. The apparatus may be used to sense an electrical arc occurring in the insulation of the wire.
摘要:
An electrical safety device is disclosed which utilizes a sensor conductor configured in a continuous loop and disposed in an electrical component so as to sense overtemperature or mechanical damage over a length or wide area of the component. The sensor may be simple insulated or non insulated copper wire. A low voltage potential is maintained across the sensor conductor. The sensor circuitry includes ambient temperature compensation.