Apparatus and method for validating leak survey results

1. An optical gas imaging (OGI) leak survey system, comprising:

an infrared (IR) thermography camera capable of capturing an infrared image of a gas plume, a leak survey result being obtained from the infrared image of the gas plume;

a temperature sensor to measure a temperature of the gas plume or ambient air; and

a validation system for validating the leak survey result obtained from the infrared image, the validation system coupled to the infrared thermography camera and coupled to the temperature sensor, the validation system including a machine readable storage medium that provides instructions that cause a machine apparatus to perform operations to validate the leak survey result, the operations comprising:

acquiring an apparent temperature of each pixel of the infrared image of a scene;

acquiring a temperature of the gas plume or ambient air from the temperature sensor;

calculating a temperature difference of said each pixel between the apparent temperature of said each pixel and the temperature of the gas plume or ambient air;

comparing the temperature difference of said each pixel to a predetermined threshold value; and

identifying areas in the scene where absolute values of the temperature difference are smaller than the predetermined threshold value, and identifying the areas in the scene as unsuitable for an OGI leak survey and as the leak survey for these areas is invalid.

2. The OGI leak survey system of the claim 1 , comprised of the infrared thermography camera capable of measuring an apparent temperature for each pixel of the infrared image of the scene, the apparent temperature being a temperature calculated based on blackbody calibration and total infrared radiance received by the infrared thermography camera, including infrared energy emitted by a background, infrared energy reflected by the background and infrared energy transmitted through the background.

3. The OGI leak survey system of the claim 1 , comprised of said acquiring the temperature of the gas plume including measuring an ambient temperature.

4. The OGI leak survey system of the claim 3 , comprised of said measuring the ambient temperature including measuring an ambient temperature around the equipment being inspected for possible leak.

5. The OGI leak survey system of the claim 1 , comprised of the temperature sensor being attached to the infrared thermography camera.

6. The OGI leak survey system of the claim 1 , comprised of said determining whether the leak survey result of the infrared thermography camera is valid including determining that the leak survey result is valid at a pixel if an absolute value of the temperature difference between the said pixel and the ambient air is no less than the predetermined threshold value.

7. A validation system for validating a leak survey result obtained from an OGI infrared camera, the validation system coupled to an infrared thermography camera that captures the infrared image of a scene, the validation system including a machine readable storage medium that provides instructions that cause a machine apparatus to perform operations to validate the leak survey result, the operations comprising:

acquiring an apparent temperature of each pixel of the infrared image of the scene;

acquiring a temperature of the gas plume or ambient air from a temperature sensor that is coupled to the validation system;

calculating a temperature difference of said each pixel between the apparent temperature of said each pixel and the temperature of the gas plume or ambient air;

comparing the temperature difference of said each pixel to a predetermined threshold value; and

identifying areas in the scene where absolute values of the temperature difference are smaller than the predetermined threshold value, and identifying the areas in the scene as unsuitable for an OGI leak survey and as the leak survey for these areas is invalid.

8. The validation system of the claim 7 , comprised of the temperature of said each pixel of the infrared image of the scene being an apparent temperature of said each pixel, the apparent temperature of said each pixel being produced from the infrared thermography camera, the apparent temperature being a temperature calculated based on blackbody calibration and total infrared radiance received by the infrared thermography camera, including infrared energy emitted by a background, infrared energy reflected by the background and infrared energy transmitted through the background.

9. The validation system of the claim 7 , comprised of the temperature of the gas plume being an ambient temperature measured by the temperature sensor.

10. The validation system of the claim 7 , comprised of said determining whether the leak survey result of the infrared thermography camera is valid including determining that the leak survey result is valid at a pixel if an absolute value of the temperature difference of the pixel is no less than the threshold value.

11. A method for validating a leak survey result, the method comprising:

capturing an infrared image of a scene from which the leak survey result is to be obtained, the infrared image being captured by an infrared camera system;

acquiring an apparent temperature of each pixel of the infrared image of the scene;

acquiring a temperature of the gas plume or ambient air;

calculating a temperature difference of said each pixel between the apparent temperature of said each pixel and the temperature of the gas plume or ambient air;

comparing the temperature difference of said each pixel to a predetermined threshold value; and

identifying areas in the scene where absolute values of the temperature difference are smaller than the predetermined threshold value, and identifying the areas in the scene as unsuitable for an OGI leak survey and as the leak survey for these areas is invalid.

12. The method of the claim 11 , comprised of the infrared camera system including an infrared thermography camera that is capable of producing an apparent temperature for each pixel, the apparent temperature being a temperature calculated based on blackbody calibration and total infrared radiance received by the infrared thermography camera, including infrared energy emitted by a background, infrared energy reflected by the background, and infrared energy transmitted through the background.

13. The method of the claim 12 , comprised of the infrared image of the scene being captured by the infrared thermography camera.

14. The method of the claim 11 , comprised of the background temperature of said each pixel of the infrared image of the scene being an apparent temperature of said each pixel.

15. The method of the claim 11 , comprised of said acquiring the temperature of the gas plume including measuring an ambient temperature.

16. The method of the claim 15 , comprised of said measuring the ambient temperature including measuring an ambient temperature around the equipment being inspected for gas leak.

17. The method of the claim 11 , comprised of said determining whether the leak survey result of the infrared camera system is valid including determining that the leak survey result is valid at a pixel if an absolute value of the temperature difference of the pixel is no less than the threshold value.