Method and apparatus for discrimination of sources in stray voltage detection

1. An apparatus for discriminating between electric field sources, comprising:

a mobile detection system comprising:

a sensor probe for remotely measuring an electric field generated by an electric field source in a patrolled area, wherein the sensor probe measures the electric field while traversing the patrolled area; and

a processor, coupled to the sensor probe, for processing data received from the sensor probe to generate a first field strength and at least a second field strength for determining whether the electric field source is potentially hazardous, wherein the first field strength is a measure of the electric field at a first frequency and the at least a second field strength is a measure of the electric field at at least a second frequency.

2. The apparatus of claim 1 , wherein the first and the at least a second field strength are graphically displayed on a display system for determining whether the electric field source is potentially hazardous.

3. The apparatus of claim 1 , wherein the processor generates an indication of whether the electric field source is potentially hazardous based on a comparison of the first and the at least a second field strength.

4. The apparatus of claim 1 , wherein the first frequency is a fundamental frequency of a power distribution system.

5. The apparatus of claim 1 , wherein the first field strength and the at least a second field strength are each normalized with respect to time and amplitude.

6. The apparatus of claim 2 , further comprising a location sensor for obtaining location information pertaining to the patrolled area, wherein a graphical display of the first and the at least a second field strength is correlated with the location information.

7. The apparatus of claim 3 , wherein the comparison comprises comparing at least one ratio based on at least two of the first and the at least a second field strength to at least one threshold.

8. The apparatus of claim 4 , wherein the at least a second frequency is at least one harmonic of the fundamental frequency.

9. The apparatus of claim 6 , wherein the location information is visual imagery.

10. A method for discriminating between electric field sources, comprising:

remotely measuring, by a mobile sensor probe traversing a patrolled area, an electric field generated by an electric field source in the patrolled area;

generating, based on remotely measuring the electric field, electrical signals representing strength of the electric field; and

computing, at a processor, based on the electrical signals, a first field strength and at least a second field strength for determining whether the electric field source is potentially hazardous, wherein the first field strength is a measure of the electric field at a first frequency and the at least a second field strength is a measure of the electric field at at least a second frequency.

11. The method of claim 10 , further comprising graphically displaying the first and the at least a second field strength for determining whether the electric field source is potentially hazardous.

12. The method of claim 10 , further comprising:

comparing, at the processor, the first and the at least a second field strength; and

generating, based on the comparing, an indication of whether the electric field source is potentially hazardous.

13. The method of claim 10 , wherein the first frequency is a fundamental frequency of a power distribution system.

14. The method of claim 10 , wherein the first field strength and the at least a second field strength are each normalized with respect to time and amplitude.

15. The method of claim 11 , further comprising:

obtaining location information pertaining to the patrolled area;

correlating the first and the at least a second field strength with the location information; and

displaying the location information correlated with the first and the at least a second field strength.

16. The method of claim 12 , wherein comparing the first and the at least a second field strength comprises comparing at least one ratio based on at least two of the first and the at least a second field strength to at least one threshold.

17. The method of claim 13 , wherein the at least a second frequency is at least one harmonic of the fundamental frequency.

18. The method of claim 15 , wherein the location information is visual imagery.