Two-color flame imaging pyrometer

• US 20070177650A1
• Filed: 01/31/2006
• Published: 08/02/2007
• Est. Priority Date: 01/31/2006
• Status: Abandoned Application

• Current Assignee: Diamond Power International Incorporated (Babcock International Group PLC)
• Original Assignee: Diamond Power International Incorporated (Babcock International Group PLC)
• Inventors: Youssef, Simon, Huston, John
• Application Number:
  US11/343,653
• Publication Number:
  US 20070177650A1
• Time in Patent Office: Days
• US Class Current: 374/130
• CPC Class Codes: G01J 5/0014 for sensing the radiation from gases, flames
• CPC Class Codes: G01J 5/0044 Furnaces, ovens, kilns G01J5/0007, G01J5/004 take precedence
• CPC Class Codes: G01J 5/025 Interfacing a pyrometer to an external device or network; User interface
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0802 Optical filters
• CPC Class Codes: G01J 5/0846 having multiple detectors for performing different types of detection, e.g. using radiometry and reflectometry channels
• CPC Class Codes: G01J 5/602 using selective, monochromatic or bandpass filtering

Abstract

The system uses a color camera and an optical system to map two colors emitted from an object such as a furnace, boiler combustion zone, or burner flame into a temperature image. The color camera utilizes a color video chip with interspersed pixels for each color to reduce alignment issues and utilize the same optical path. In addition, the optical system utilizes a dual band pass optical filter thereby eliminating the number of optical elements and minimizing radiation loss through the optical system thereby improving the dynamic range of the system.

Claims

1. A pyrometer system for measuring the temperature of an object emitting light radiation, the pyrometer system comprising:

a color video camera, the color video camera having a color detector including a plurality of picture elements, the plurality of picture elements including a first set of elements configured to detect a first color of light, the second set of elements being configured to detect a second color of light, wherein the first and second set of elements are interspaced on the color detector;

an optical system for focusing optical radiation onto the color detector, the optical system including at least one filter in optical communication with the color detector, the at least one filter transmitting a first band corresponding to the first color of light and a second band corresponding to the second color of light; and

a processor being configured to determine the temperature of the object based on signals from the first and second set of picture elements.

2. The system according to claim 1, wherein the light radiation from the object travels along a single optical path.

3. The system according to claim 1, wherein the color video camera is an RGB color video camera.

7. The system according to claim 1, wherein the color camera is a CyGrMgYe color video camera.

8. The system according to claim 7, wherein the at least one filter is configured to block light outside a first and second band and wherein the first band is centered about 450 nanometers and the second band is centered at about 550 nanometers.

9. The system according to claim 7, wherein the at least one filter is configured to block light outside a first and second band and wherein the first band is centered about 450 nanometers and the second band is centered at about 540 nanometers.

10. The system according to claim 7, wherein the at least one filter is configured to block light outside a first and second band and wherein the first band is centered about 450 nanometers and the second band is centered at about 610 nanometers.

11. The system according to claim 7, wherein the at least one filter is configured to block light outside a first and second band and wherein the first band is centered about 510 nanometers and the second band is centered at about 610 nanometers.

12. The system according to claim 7, wherein the at least one filter is configured to block light outside a first and second band and wherein the first band is centered about 540 nanometers and the second band is centered at about 610 nanometers.

13. The system according to claim 1, wherein the system is configured to calculate the temperature based on the equation T=K*(W₁/W₂)), where T is the temperature of the object, W₁ is the measured spectral emittance of the first set of elements, and W₂ is the measured spectral emittance of the second set of elements.

4. The system according to claim 4, wherein the at least one filter is configured to block light outside a first and second band and wherein the first band is centered about 470 nanometers and the second band is centered at about 540 nanometers.

5. The system according to claim 4, wherein the at least one filter is configured to block light outside a first and second band and wherein the first band is centered about 470 nanometers and the second band is centered at about 650 nanometers.

6. The system according to claim 4, wherein the at least one filter is configured to block light outside a first and second band and wherein the first band is centered about 540 nanometers and the second band is centered at about 650 nanometers.

14. A pyrometer system for measuring the temperature of an object emitting light radiation, the pyrometer system comprising:

a color video camera, the color video camera having a color detector including a plurality of picture elements, the plurality of picture elements including a first set of elements configured to detect a first sensitivity band of visible light, the second set of elements being configured to detect a second sensitivity band of visible light, wherein the first and second set of elements are interspaced on the color detector;

an optical system for focusing optical radiation onto the color detector wherein the optical system includes a dual mode optical filter having a first wavelength band narrower than the first sensitivity band of visible light and a second wavelength band narrower than the second sensitivity band of visible light, and the light radiation from the object travels along a single optical path; and

a processor being configured to determine the temperature of the object based on signals from the first and second set of picture elements.

15. The system according to claim 14, wherein the color video camera is an RGB color video camera.

16. The system according to claim 14, wherein the color camera is a CyGrMgYe color video camera.

17. The system according to claim 14, wherein the system is configured to calculate the temperature based on the equation T=K*(W₁/W₂)), where T is the temperature of the object, W₁ is the measured spectral emittance of the first set of elements, and W₂ is the measured spectral emittance of the second set of elements.