Apparatus and sensor unit for monitoring changes in a physical quantity with time
First Claim
1. Apparatus, for monitoring changes in a physical quantity with time, said apparatus including a reader unit and at least one sensor unit, said reader unit including an r.f. power source, said sensor unit comprising a plastic body hermetically encapsulating a means arranged for measuring said physical quantity at predetermined time intervals and a data storage means arranged to store measurements of said physical quantity with corresponding time data, said plastic body also hermetically encapsulating communication means for transferring said measurements of said physical quantity and said time data from said sensor unit to said reader unit, and said sensor unit also carrying inductive coupling means arranged to receive energy from said r.f. power source of said reader unit to power said communication means.
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Accused Products
Abstract
Apparatus for monitoring changes in a physical quantity with time comprises a reader unit and at least one sensor unit containing electronic components arranged to measure said quantity at predetermined time intervals and to store measurement data with corresponding time data. Each sensor unit also contains communication means for transferring said measurement data and said time data from the sensor unit to the reader unit, and the sensor unit also contains an inductive coupling means to receive energy from the reader unit to power the communication means. Each sensor unit is encapsulated with a food grade plastic and is typically the size of a credit card, thereby providing a small and relatively inexpensive temperature monitoring device for use in the transport and storage of foodstuffs.
110 Citations
31 Claims
- 1. Apparatus, for monitoring changes in a physical quantity with time, said apparatus including a reader unit and at least one sensor unit, said reader unit including an r.f. power source, said sensor unit comprising a plastic body hermetically encapsulating a means arranged for measuring said physical quantity at predetermined time intervals and a data storage means arranged to store measurements of said physical quantity with corresponding time data, said plastic body also hermetically encapsulating communication means for transferring said measurements of said physical quantity and said time data from said sensor unit to said reader unit, and said sensor unit also carrying inductive coupling means arranged to receive energy from said r.f. power source of said reader unit to power said communication means.
- 12. A sensor unit, for monitoring changes in a physical quantity with time, comprising a body formed of a food-grade plastic, a means arranged for measuring said physical quantity at predetermined time intervals hermetically sealed within said body, a data storage means arranged to store measurements of said physical quantity with corresponding time data hermetically sealed with said body, communication means for transmitting said measurements of said physical quantity and said time data, said communication means being hermetically sealed within said body, and inductive coupling means arranged to receive energy to power said communication means.
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21. A sensor unit, for monitoring changes in a physical quantity with time, comprising:
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a plastic body having a smooth exterior surface, a measuring means arranged for measuring said physical quantity, a clock circuit arranged to provide time data, a processor arranged to operate said measuring means for a very short time at relatively long intervals, a data storage means arranged to record the measurements of said physical quantity and corresponding time data, a battery arranged to provide battery power to said measuring means and said clock circuit and said processor and said data storage means, a communication means for transmitting data from said data storage means to a reader unit, and an inductive coupling means for receiving r.f. power from said reader unit whenever said inductive coupling means is inductively coupled with said reader unit, said inductive coupling means being arranged to couple said r.f. power to said communication means, and said measuring means, said clock circuit, said processor, said data storage means, said battery, said communication means and said inductive coupling means are all completely and hermetically sealed within said plastic body. - View Dependent Claims (22)
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23. A food temperature recording unit comprising:
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a plastic body having a smooth exterior surface, a temperature measuring means arranged for measuring temperature close to said smooth exterior surface, a clock circuit arranged to provide time data, a processor arranged to operate said temperature measuring means for a very short time at relatively long intervals, a data storage means arranged to record the measured temperature and the corresponding time data, a first power source arranged to power said temperature measuring means and said clock circuit and said data storage means, a communication means for transmitting data from said data storage means to a reader unit positioned outside said body, and an inductive coupling means arranged for receiving power from a second power source outside said body and arranged to couple said power to said communication means, and said plastic body completely and hermetically surrounds said temperature measuring means, said clock circuit, said processor, said data storage means, said first power source, said communication means and said inductive coupling means. - View Dependent Claims (24, 25)
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- 26. A method of recording changes in the temperature of a consignment of goods over a period of time, including packing a hermetically sealed sensor unit with said consignment of goods, using the sealed sensor unit to measure the temperature of said consignment of goods for a very short period of time at predetermined relatively long time intervals, recording within the sensor unit the measured temperature and time data using a source of power within said sealed sensor unit, and subsequently retrieving the temperature and time data from the sealed sensor unit by using a second source of power from outside the sealed sensor unit.
Specification