System and method for detecting tampering of a utility meter

• US 20090243866A1
• Filed: 03/31/2008
• Published: 10/01/2009
• Est. Priority Date: 12/26/2007
• Status: Active Grant

• Current Assignee: Elster Electricity LLC (Honeywell International Inc.)
• Original Assignee: Elster Electricity LLC (Honeywell International Inc.)
• Inventors: Murphy, Michael A.
• Granted Patent: US 7,847,690 B2
• Time in Patent Office: Days
• US Class Current: 340/635
• CPC Class Codes: G01R 22/066 Arrangements for avoiding or indicating fraudulent use
• CPC Class Codes: G06Q 50/06 Energy or water supply

Abstract

A tamper alarm circuit for detecting a tampered condition of a utility meter is disclosed. The tamper alarm circuit has a transducer coupled to an amplification circuit which is coupled to a detection circuit, the detection circuit generating an alarm condition when the detection circuit determines that a voltage signal generated by the transducer and amplified by the amplification circuit has reached a predetermined threshold.

Claims

1. A tamper alarm circuit for detecting a tampered condition of a utility meter comprising:

a transducer coupled to;

an amplification circuit coupled to;

a detection circuit, the detection circuit generating an alarm condition when the detection circuit determines that a voltage signal generated by the transducer and amplified by the amplification circuit has reached a predetermined threshold.

2. The tamper detection circuit of claim 1 wherein the detection circuit further comprises a comparator stage and an amplification stage.

3. The tamper detection circuit of claim 1 wherein the utility meter is a watt-hour meter.

4. The tamper detection circuit of claim 1 wherein the transducer is a piezoelectric transducer ceramic capacitor.

5. The tamper detection circuit of claim 4 wherein the piezoelectric transducer is a ceramic capacitor.

6. The tamper detection circuit of claim 1 wherein the utility meter is a gas meter.

7. The tamper detection circuit of claim 1 wherein the utility meter is a water meter.

8. A utility meter comprising:

a utility resource monitoring circuit, the utility resource monitoring circuit monitoring the amount of resources used by a consumer, the utility resource monitoring circuit communicating with;

a tamper alarm circuit, the tamper alarm circuit further comprising

a transducer coupled to;

an amplification circuit coupled to;

a detection circuit, the detection circuit generating an alarm condition when the detection circuit determines that a voltage signal generated by the transducer and amplified by the amplification circuit has reached a predetermined threshold.

9. The utility meter of claim 8 wherein the tamper detection circuit determines that the voltage signal has reached the predetermined threshold after the utility monitoring circuit has detected a power failure.

10. The utility meter of claim 8 wherein the tamper detection circuit determines that the voltage signal has reached the predetermined threshold before the utility monitoring circuit has detected a power failure

11. The utility meter of claim 8 wherein the utility meter is a watt-hour meter.

12. The utility meter of claim 8 wherein the utility meter is a gas meter.

13. The utility meter of claim 8 wherein the transducer is a piezoelectric transducer.

14. The utility meter of claim 13 wherein the piezoelectric transducer is a ceramic capacitor.

15. A method for detecting a tamper condition alarm in a utility meter comprising:

providing a transducer coupled to an amplification circuit which is coupled to a detection circuit,

determining that a voltage signal generated by the transducer and amplified by the amplification circuit has reached a predetermined threshold,

generating an alarm condition when the detection circuit determines that the amplified voltage signal has reached the predetermined threshold.

16. The method of claim 15 wherein the step of determining that the voltage signal has reached the predetermined threshold occurs after the utility meter has detected a power failure.

17. The method of claim 15 wherein the step of determining that the voltage signal has reached the predetermined threshold occurs before the utility meter has detected a power failure.

18. The method of claim 15 wherein the utility meter is a watt-hour meter.

19. The method of claim 15 wherein the utility meter is a water meter.

20. The method of claim 15 wherein the transducer is a piezoelectric transducer.

21. The method of claim 20 wherein the piezoelectric transducer is a ceramic capacitor.