Schlumberger Resource Management Services, Inc.

Gary W Morand

Brad Smith

Brent Cain

Method and apparatus facilitate improved sensing of tampering of an electrically powered device, such as an electric watt-hour meter installed at a residence for metering the amount of electric energy consumed at the residence. The detected tampering involves an effort to remove the electric meter from its power socket, to interrupt the metering of electric energy consumption, or to otherwise gain access for diverting electric energy. Removal of the electric meter from its power socket interrupts power to the meter. The method and apparatus senses motion of the meter and sets a &ldquo;Tamper Flag&rdquo; in a non-volatile memory. The &ldquo;Tamper Flag&rdquo; is saved (i.e., is not cleared from the non-volatile memory) if loss of power to the meter occurs within a predetermined period of time. The &ldquo;Tamper Flag&rdquo; is cleared if there is no loss of power to the meter within the predetermined period of time. Upon detecting a resumption of power after a loss of power to the meter, an indication of sensed tampering is made if the &ldquo;Tamper Flag&rdquo; is set.

Method and apparatus for indicating meter tampering

An improved process ensures to the extent possible that the usage memory of an electronically-based electricity meter is always in a state that most recent data may be retrieved. Two separate areas or pages of memory are maintained and updated as to quantitative consumptions, e.g., kiloWatt-hour. Preferably a non-volatile form of memory is used. The older of the two data memories is updated, based on a data validation check. The approach ensures that a previous value is always retained, to prevent full data loss in the event that the power goes down. If one area of memory becomes corrupted, the other value can be retrieved and verified so as to prevent loss of both memory areas, before a subsequent data reading (such as kWh or a unit of time for a kW reading). Use of a relatively smaller unit of measure prevents any significant adverse affects to the accuracy of the value stored. In other words, the maximum data lost is limited to the chosen unit of measure since the most recent previous update.

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Duluth, GA, United States of America

Gary W Morand