Method for sensing an electric field

• US 7,253,642 B2
• Filed: 09/13/2005
• Issued: 08/07/2007
• Est. Priority Date: 12/23/2004
• Status: Active Grant

• Current Assignee: Osmose Utilities Services Incorporated (Osmose Holdings Incorporated)
• Original Assignee: Power Survey Company
• Inventors: Kalokitis, David, Zalud, Peter, Polyzois, Christos Alkiviadis, Berends, David Christopher
• Primary Examiner(s): Hirshfeld; Andrew H.
• Assistant Examiner(s): Dole; Timothy J
• Application Number:
  US11/224,910
• Publication Number:
  US 20060139032A1
• Time in Patent Office: 693 Days
• Field of Search: 324/686, 324/457
• US Class Current: 324/686
• CPC Class Codes: G01R 23/16 Spectrum analysis; Fourier analysis
• CPC Class Codes: G01R 29/0814 Field measurements related to measuring influence on or from apparatus, components or humans EMC, EMI and similar testing in general G01R31/001, e.g. in ESD, EMI, EMC, EMP testing, measuring radiation leakage; detecting presence of micro- or radiowave emitters; dosimetry; testing shielding; measurements related to lightning
• CPC Class Codes: G01R 29/085 for detecting presence or location of electric lines or cables fault detection G01R31/50; fault location G01R31/08

Abstract

A method for sensing an electric field includes processing digitized electric field signals, e.g., from an electric field sensing probe. The processing may include performing a Fast Fourier Transform of the digitized electric field signals to provide an indication of the magnitude of the electric field, and may include processing the digitized electric field signals at a rate that is related to the speed at which a movable sensing probe is moving. The method may include performing unweighted and/or weighted averaging in relation to processing electric field data, setting a comparison threshold, providing a human perceivable indication, or a combination of the foregoing.

Claims

1. A method for detecting an electric field comprising:

receiving a digitized representation of an electric filed sensed by at least one electric sensing probe adaptalbe for mobility about a plurality of electric fields;

determining a speed at which the at least one electric field sensing probe is moving;

processing the digitized representation of the electric field, wherein signal averaging associated with the digitized representation of the electric field is adjusted commensurate with the speed at which the electric field sensing probe is moving; and

comparing the processed digitized representation of the electric field with a threshold and providing a human perceivable indication of the detected electric field.

2. The method of claim 1, wherein receiving the digitized representation of the electric field includes:

placing an electric field sensing probe having at least one pair of spaced apart electrically conductive electrodes in an electric field; and

digitizing electrical signals produced by the electric field sensing probe in response to the electric field.

3. The method of claim 2 further comprising:

providing a pair of spaced apart electrically conductive auxiliary electrodes, wherein the electric field sensing probe is disposed in a space defined between the pair of spaced apart electrically conductive auxillary electrodes; and

selectively electrically connecting the pair of spaced electrically conductive electrodes together, or selectively electrically connecting the pair of spaced apart electrically conductive electrodes to a common reference, or selectively electrically connecting a pair of spaced apart electrically conductive electrodes together and to a common reference.

4. The method of claim 1 wherein averaging the digitized representation of the electric field further comprises:

averaging using an unweighted average;

or

averaging using an unweighed average including one or more predetermined weighting factors;

or

averaging using a weighted average including one or more selectable weighting factors;

or

any combination of the foregoing.

5. The method of claim 4 wherein the weighting factor applied when the digitized representation of the electric field exceeds the threshold is substantially smaller than the weighting factor applied when the digitized representation of the electric field does not exceed the threshold.

6. The method of claim 1 wherein determining the speed includes measuring speed, or measuring distance, or sensing wheel speed, or sensing wheel revolution, or GPS locating, or imaging, or video imaging, or TV camera imaging, or any combination of the foregoing, for determining the speed.

7. A method for detecting an electric field comprising:

receiving a digitized representation of an electric field;

processing the digitized representation of the electric field, wherein processing of the digitized representation of the electric field includes performing a Fast Fourier Transform on the digitized representation of the electric field at a rate that is a multiple of the expected frequency of the electric field; and

comparing the Fast Fourier Transformed digitized representation of the electric field with a threshold and providing a human perceivable indication of the detected electric field. field with a threshold to provide a human perceivable indication of the electric field.

8. The method of claim 7 wherein said receiving the digitized representation of the electric field includes:

placing an electric field sensing probe having at least one pair of spaced apart electrically conductive electrodes in an electric field; and

digitizing electrical signals produced by the electric field sensing probe in response to the electric field.

9. The method of claim 8 further comprising:

placing a pair of spaced apart electrically conductive auxiliary electrodes, wherein the electric field sensing probe is disposed in a space defined between the pair of spaced apart electrically conductive auxiliary e;

ectrpdes; and

selectively electrically connecting the pair of spaced apart electrically conductive electrodes together, or selectively electrically connecting the pair of spaced apart electrically conductive electrodes to a common reference, or selectively electrodes connecting the pair of spaced apart electrically conductive electrodes together and to a common reference.

10. The method of claim 8 wherein processing the digitized representation of the electric field further comprises:

averaging the Fast Fourier Transformed digitized representation of the electric field at a rate that is related to a speed at which the electric field sensing probe is moving, and

comparing the Fast Fourier Transformed digitized representation of the electric field with a threshold representative of the averaged Fast Fourier Transformed digitized representation of the electric field to provide the human perceivable indication of the electric field.

11. The method of claim 10 wherein averaging the Fast Fourier Transformed digitized representation of the electric field further comprises:

averaging using an unweighted average;

or

averaging using a weighted average including one or more predetermined weighting factors;

or

averaging using a weighted average including one or more selectable weighting factors;

or

any combination of the foregoing.

12. The method of claim 11 wherein the weighting factor applied when the Fast Fourier Transformed digitized representation of the electric field exceeds the threshold is substantially smaller than the weighting factor applied when the Fast Fourier Transformed digitized representation of the electric field does not exceed the threshold.

13. The method of claim 10 further comprising measuring speed, or measuring distance, or sensing wheel speed, or sensing wheel revolution, or GPS locating, or imaging, or video imaging, or TV camera imaging, or any combination of the foregoing, for determining the speed at which the electric field sensing probe is moving.

14. The method of claim 7 further comprising measuring speed, or measuring distance, or sensing wheel speed, or sensing wheel revolution, or GPS locating, or imaging, or video imaging, or TV camera imaging, or any combination of the foregoing, for determining a location corresponding to the human perceivable indication of the detected electric field.

15. The method of claim 7 wherein the human perceivable indication of the electric field includes a visual indication, or any combination of the foregoing.

16. The method of claim 15 wherein the audible indication is configured to emit a tone having a pitch that is logarithmically related to electric field strength.

17. The method of claim 16 wherein:

the logarithmic relationship produces about a one octave change in pitch of the audible indication tone for each about 10 dB change in electric field strength;

or

the pitch is changed by an increment that is less than or equal to about an eighth of a step in an equal tempered chromatic scale;

or

the pitch is in a range from about 70 Hz to about 2.5-3 KHz;

or

any combination of the foregoing.

18. The method of claim 7 further comprising:

storing the Fast Fourier Transformed digitized representation of the electric field;

or

averaging the Fast Fourier Transformed digitized representation of the electric field and storing the average thereof;

or

storing the Fast Fourier Transformed digitized representation of the electric field and a representation of speed, or distance, or location, or a combination of the foregoing;

or

averaging the Fast Fourier Transformed digitized representation of the electric field and storing the average thereof and a representation of speed, or distance, or location, or a combination of the foregoing;

or

storing the human perceivable indication of the electric field;

or

any combination of the foregoing.