Method for sensing an electric field

• US 20060139032A1
• Filed: 09/13/2005
• Published: 06/29/2006
• Est. Priority Date: 12/23/2004
• Status: Active Grant

• Current Assignee: Osmose Utilities Services Incorporated (Osmose Holdings Incorporated)
• Original Assignee: Power Survey Corporation
• Inventors: Kalokitis, David, Zalud, Peter, Polyzois, Christos Alkiviadis, Berends, David Christopher
• Granted Patent: US 7,253,642 B2
• Time in Patent Office: Days
• US Class Current: 324/457
• 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 sensing an electric field comprising:

receiving a digitized representation of an electric field sensed by a movable electric field sensing probe;

sensing a speed at which the movable electric field sensing probe is moving;

processing the digitized representation of the electric field at a rate that is related to the speed at which the movable electric field sensing probe is moving for defining a threshold;

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 the threshold to provide a human perceivable indication of the electric field.

2. The method of claim 1 wherein said receiving a digitized representation includes:

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

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

4. The method of claim 1 wherein said processing the digitized representation of the electric field includes averaging the Fast Fourier Transformed digitized representation of the electric field at a rate that is related to the speed at which the movable electric field sensing probe is moving for defining the threshold, and

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

5. A method for sensing an electric field comprising:

receiving a digitized representation of an electric field sensed by a movable electric field sensing probe;

sensing a speed at which the movable electric field sensing probe is moving;

processing the digitized representation of the electric field at a rate that is related to the speed at which the movable electric field sensing probe is moving; and

comparing the processed digitized representation of the electric field with a threshold to provide a human perceivable indication of the electric field.

6. The method of claim 5 wherein said receiving a digitized representation includes:

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

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

7. The method of claim 6 further comprising:

placing a pair of spaced apart electrically conductive auxiliary electrodes to dispose the sensing probe in a space defined between the pair of spaced apart electrically conductive auxiliary electrodes; 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 electrically connecting the pair of spaced apart electrically conductive electrodes together and to a common reference.

8. The method of claim 5 wherein said processing comprises:

averaging the digitized representation of the electric field at a rate that is related to the speed at which an electric field sensing electrode is moving, and wherein said comparing comprises;

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

9. The method of claim 8 wherein said averaging 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.

10. The method of claim 9 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.

11. The method of claim 5 wherein said sensing a 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.

12. A method for sensing an electric field comprising:

receiving a digitized representation of an electric field;

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 to provide a human perceivable indication of the electric field.

13. The method of claim 12 wherein said receiving a digitized representation 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.

14. The method of claim 13 further comprising:

placing a pair of spaced apart electrically conductive auxiliary electrodes to dispose the electric field sensing probe in a space defined between the pair of spaced apart electrically conductive auxiliary electrodes; 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 electrically connecting the pair of spaced apart electrically conductive electrodes together and to a common reference.

15. The method of claim 12 wherein said comparing comprises:

averaging the Fast Fourier Transformed digitized representation of the electric field at a rate that is related to a speed at which an electric field sensing electrode 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.

16. The method of claim 15 wherein said averaging 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.

17. The method of claim 16 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.

18. The method of claim 15 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 electrode is moving.

19. The method of claim 12 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 defining a location corresponding to the human perceivable indication of the electric field.

20. The method of claim 12 wherein the human perceivable indication of the electric field includes a visual indication, or an audible indication, or both.

21. The method of claim 20 wherein the audible indication includes a tone having a pitch that is logarithmically related to electric field strength.

22. The method of claim 21 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.

23. The method of claim 12 further comprising:

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

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.