Gas detection systems and methods with search directions

• US 9,719,879 B1
• Filed: 01/03/2013
• Issued: 08/01/2017
• Est. Priority Date: 05/14/2012
• Status: Active Grant

• Current Assignee: Picarro, Inc.
• Original Assignee: Picarro, Inc.
• Inventors: Tan, Sze Meng, Crosson, Eric R., Rella, Chris W.
• Primary Examiner(s): Charioui, Mohamed
• Application Number:
  US13/733,861
• Time in Patent Office: 1,671 Days
• Field of Search: 702 51, 702188
• CPC Class Codes: F02M 65/006 Measuring or detecting fuel leakage of fuel injection apparatus
• CPC Class Codes: G01M 3/00 Investigating fluid-tightness of structures
• CPC Class Codes: G01M 3/007 Leak detector calibration, standard leaks G01M3/207 takes precedence
• CPC Class Codes: G01M 3/04 by detecting the presence of fluid at the leakage point
• CPC Class Codes: G01M 3/16 using electric detection means G01M3/045, G01M3/06, G01M3/12, G01M3/20, G01M3/24, G01M3/26 take precedence
• CPC Class Codes: G01M 3/24 using infrasonic, sonic, or ultrasonic vibrations
• CPC Class Codes: G01M 3/26 by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
• CPC Class Codes: G01M 3/28 for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds
• CPC Class Codes: G01M 3/2807 for pipes G01M3/2892, G01M3/30 take precedence
• CPC Class Codes: G01M 3/2892 for underground fuel dispensing systems G01M3/30 takes precedence
• CPC Class Codes: G01M 3/38 by using light G01M3/02 takes precedence
• CPC Class Codes: G01W 1/00 Meteorology
• CPC Class Codes: G06F 15/00 Digital computers in general details G06F1/00 – G06F13/00; Data processing equipment in general
• CPC Class Codes: G06F 16/29 Geographical information databases

Abstract

In some embodiments, at least one processor determines a range of search directions to a suspected gas leak source by receiving data representative of a plurality of wind direction measurements relative to a geo-referenced location of at least one gas concentration measurement point. The range of search directions extending from the location of the gas concentration measurement point is calculated according to a variability of the wind direction measurements.

Claims

1. A method comprising:

performing a gas leak detection survey by

measuring a plurality of gas concentration values at a corresponding plurality of measurement points using a gas concentration measurement device carried by a moving vehicle along a survey path,

determining a plurality of geospatially-referenced locations of the plurality of measurement points using a positioning device carried by the moving vehicle, and

measuring a plurality of wind direction values using a wind direction determination device carried by the moving vehicle, wherein the plurality of wind direction values are measured within a time interval during which the plurality of gas concentration values are measured, the time interval being less than or equal to 2 minutes;

determining, using at least one hardware processor, a range of search directions to a suspected gas leak source extending from a location of a gas concentration measurement point according to a variability of the wind direction values, wherein the range of search directions defines a width of a graphical indicator of the variability of the wind direction values; and

employing the range of search directions to identify a location of the suspected gas leak source, to facilitate a repair of the gas leak source.

2. The method of claim 1, wherein the variability comprises a variance or standard deviation of the wind direction values.

3. The method of claim 2, wherein the range of search directions is proportional to the standard deviation of the wind direction values.

4. The method of claim 1, further comprising employing the at least one processor to determine a representative wind direction relative to the gas concentration measurement point.

5. The method of claim 4, wherein the representative wind direction comprises a mean, median or mode of the wind direction values.

6. The method of claim 1, further comprising employing the at least one processor to determine, according to wind speed data relative to the gas concentration measurement point, a maximum detection distance value representative of an estimated maximum distance from the suspected gas leak source at which a gas leak is detectable by the survey.

7. The method of claim 6, wherein the maximum detection distance value is further determined according to data representative of atmospheric stability conditions along the survey path.

8. The method of claim 1, wherein the location of the gas concentration measurement point corresponds to a peak in gas concentration identified from the plurality of gas concentration values.

9. An apparatus comprising:

a gas concentration measurement device configured to measure a plurality of gas concentration values at a corresponding plurality of measurement points along a survey path travelled by a moving vehicle conducting a gas leak detection survey, the vehicle carrying the gas concentration measurement device;

a positioning device configured to determine a plurality of geospatially-referenced locations of the plurality of measurement points;

a wind direction determination device configured to measure a plurality of wind direction values within a time interval during which the plurality of gas concentration values are measured, the time interval being less than or equal to 2 minutes; and

at least one hardware processor coupled to the gas concentration measurement device, the positioning device, and the wind direction measurement device, and programmed to determine a range of search directions to a suspected gas leak source extending from a location of a gas concentration measurement point according to a variability of the wind direction values, wherein the range of search directions defines a width of a graphical indicator of the variability of the wind direction values.

10. The apparatus of claim 9, wherein the variability comprises a variance or standard deviation of the wind direction values.

11. The apparatus of claim 10, wherein the range of search directions is proportional to the standard deviation of the wind direction values.

12. The apparatus of claim 9, wherein the at least one processor is configured to determine a representative wind direction relative to the gas concentration measurement point.

13. The apparatus of claim 12, wherein the representative wind direction comprises a mean, median or mode of the wind direction values.

14. The apparatus of claim 9, wherein the gas concentration measurement point corresponds to a peak in gas concentration identified from the plurality of gas concentration measurements.

15. The apparatus of claim 9, wherein the at least one processor is further programmed to determine, according to wind speed data relative to the gas concentration measurement point, a maximum detection distance value representative of an estimated maximum distance from the suspected gas leak source at which a gas leak is detectable by the survey.

16. The apparatus of claim 15, wherein the maximum detection distance value is further determined according to data representative of atmospheric stability conditions along the survey path.

17. A method comprising:

performing a gas leak detection survey by

measuring a plurality of gas concentration values at a corresponding plurality of measurement points using a gas concentration measurement device carried by a moving vehicle along a survey path,

determining a plurality of geospatially-referenced locations of the plurality of measurement points using a positioning device carried by the moving vehicle, and

measuring a plurality of wind direction values and a plurality of wind speed values using at least one wind measurement device carried by the moving vehicle, wherein the plurality of wind direction values and the plurality of wind speed values are measured within a time interval during which the plurality of gas concentration values are measured, the time interval being less than or equal to 2 minutes; and

determining, using at least one hardware processor, a probable direction and an estimated maximum distance to a suspected gas leak source relative to a geo-referenced location of a gas concentration measurement point, wherein the maximum distance represents an estimated maximum distance from the suspected gas leak source at which a gas leak is detectable by the survey, wherein the probable direction is determined according to the plurality of wind direction values, wherein the maximum distance is determined according to the plurality of wind speed values, and wherein the maximum distance defines a length of a graphical indicator of the maximum distance.

18. The method of claim 17, wherein the maximum distance is further determined according to data representative of atmospheric stability conditions in an area of the gas concentration measurement point.

19. The method of claim 17, wherein the location of the gas concentration measurement point corresponds to a peak in gas concentration identified from the plurality of gas concentration values.

20. An apparatus comprising:

a gas concentration measurement device configured to measure a plurality of gas concentration values at a corresponding plurality of measurement points along a survey path travelled by a moving vehicle conducting a gas leak detection survey, the vehicle carrying the gas concentration measurement device;

a positioning device configured to determine a plurality of geospatially-referenced locations of the plurality of measurement points;

at least one wind measurement device configured to measure a plurality of wind direction values and a plurality of wind speed values within a time interval during which the plurality of gas concentration values are measured, the time interval being less than or equal to 2 minutes; and

at least one hardware processor coupled to the gas concentration measurement device, the positioning device, and the at least one wind measurement device, and programmed to determine a probable direction and an estimated maximum distance to a suspected gas leak source relative to a geo-referenced location of a gas concentration measurement point, wherein the maximum distance represents an estimated maximum distance from the suspected gas leak source at which a gas leak is detectable by the survey, wherein the probable direction is determined according to the plurality of wind direction values, wherein the maximum distance is determined according to the plurality of wind speed values, and wherein the maximum di stance defines a length of a graphical indicator of the maximum distance.

21. The apparatus of claim 20, wherein the maximum distance is further determined according to data representative of atmospheric stability conditions in an area of the gas concentration measurement point.

22. The apparatus of claim 20, wherein the location of the gas concentration measurement point corresponds to a peak in gas concentration identified from the plurality of gas concentration values.

23. A non-transitory computer-readable medium encoding instructions which, when executed by a computer system, cause the computer system to:

receive a plurality of gas concentration values measured at a corresponding plurality of measurement points using a gas concentration measurement device carried by a moving vehicle along a survey path,

receive a plurality of geospatially-referenced locations of the plurality of measurement points determined using a positioning device carried by the moving vehicle, and

receive a plurality of wind direction values and a plurality of wind speed values measured using at least one wind measurement device carried by the moving vehicle, wherein the plurality of wind direction values and the plurality of wind speed values are measured within a time interval during which the plurality of gas concentration values are measured, the time interval being less than or equal to 2 minutes; and

determine a probable direction and an estimated maximum distance to a suspected gas leak source relative to a geo-referenced location of a gas concentration measurement point, wherein the maximum distance represents an estimated maximum distance from the suspected gas leak source at which a gas leak is detectable by the survey, wherein the probable direction is determined according to the plurality of wind direction values, wherein the maximum distance is determined according to the plurality of wind speed values, and wherein the distance defines a length of a graphical indicator of the maximum distance.

24. The medium of claim 23, wherein the maximum distance is further determined according to data representative of atmospheric stability conditions.

25. A non-transitory computer-readable medium encoding instructions which, when executed by a computer system, cause the computer system to:

receive a plurality of gas concentration values measured at a corresponding plurality of measurement points using a gas concentration measurement device carried by a moving vehicle along a survey path;

receive a plurality of geospatially-referenced locations of the plurality of measurement points determined using a positioning device carried by the moving vehicle, and

receive a plurality of wind direction values measured using a wind direction determination device carried by the moving vehicle, wherein the plurality of wind direction values are measured within a time interval during which the plurality of gas concentration values are measured, the time interval being less than or equal to 2 minutes; and

determine a range of search directions to a suspected gas leak source extending from a location of a gas concentration measurement point according to a variability of the wind direction values, wherein the range of search directions defines a width of a graphical indicator of the variability of the wind direction values.