Multiwavelength pyrometry systems

• US 20070290131A1
• Filed: 05/22/2006
• Published: 12/20/2007
• Est. Priority Date: 05/22/2006
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Nirmalan, Nirm Velumylum, Allen, Jason Randolph, Williams, Jeffrey Lawrence, Antel, William Joseph
• Granted Patent: US 7,633,066 B2
• Time in Patent Office: Days
• US Class Current: 250/338.1
• CPC Class Codes: G01J 5/0022 for sensing the radiation of moving bodies
• CPC Class Codes: G01J 5/0088 in turbines
• CPC Class Codes: G01J 5/04 Casings
• CPC Class Codes: G01J 5/047 Mobile mounting; Scanning arrangements
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0802 Optical filters
• CPC Class Codes: G01J 5/0808 Convex mirrors
• CPC Class Codes: G01J 5/084 Adjustable or slidable
• 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 5/10 using electric radiation detectors
• CPC Class Codes: G01J 5/485 Temperature profile
• CPC Class Codes: G01J 5/602 using selective, monochromatic or bandpass filtering

Abstract

A thermal measurement system includes a number of detectors configured to receive radiation within respective wavelength ranges. The system also includes a mirror configured to selectively direct the radiation from an object to each of the detectors. The system further includes an actuator mechanically coupled to the mirror and configured to rotate the mirror through a number of angles. The system also includes an optical and probe subsystem disposed between the object and the mirror to focus the radiation on to the mirror.

Claims

1. A thermal measurement system comprising:

a plurality of detectors configured to receive radiation within a plurality of wavelength ranges;

a mirror configured to selectively direct the radiation from an object to each of the detectors;

an actuator mechanically coupled to the mirror and configured to rotate the mirror through a plurality of angles; and

an optical and probe subsystem disposed between the object and the mirror to focus the radiation on to the mirror.

2. The thermal measurement system of claim 1, wherein the detectors are configured to receive radiation within the wavelength range of about 0.6 micrometers and greater.

3. The thermal measurement system of claim 1, wherein the plurality of detectors comprises three or more detectors.

4. The thermal measurement system of claim 1, wherein the detectors are selected from the group consisting of indium-gallium-arsenide based detectors, silicon based detectors, extended indium-gallium-arsenide based detectors and lead-antimony based detectors.

5. The thermal measurement system of claim 1, wherein the probe and optical subsystem comprises a fiber optic cable or an assembly of lenses and mirrors.

6. The thermal measuring system of claim 1, further comprising an analog to digital signal conditioner configured to convert an analog signal from each of the detectors to a digital signal.

7. The thermal measurement system of claim 1, further comprising a processor configured to receive a plurality of signals from the detectors, and output a temperature profile of the object and emissivity data based on the signals.

8. The thermal measurement system of claim 1, further comprising a plurality of filters configured to selectively filter the radiation received by the detectors.

9. The thermal measurement system of claim 1, wherein the object is a rotating object.

10. The thermal measurement system of claim 9, wherein the rotating object comprises a gas turbine blade.

11. The thermal measurement system of claim 9, configured to sample radiation at a plurality of spots on the rotating object during a revolution of the object.

12. The thermal measurement system of claim 9, further comprising a processor configured to receive a plurality of signals from the detectors and to determine a two dimensional temperature map of the rotating object.

13. A thermal measurement system comprising:

a plurality of detectors configured to receive radiation within a plurality of wavelength ranges;

a rotor configured to rotate about an axis, wherein the detectors are circumferentially arranged on the rotor;

a motor mechanically coupled to the rotor and configured to rotate the rotor about the axis; and

an optical and probe subsystem disposed between the object and the rotor and configured to focus radiation from the object onto each of the detectors.

14. The thermal measurement system of claim 13, wherein the detectors are configured to receive radiation within the wavelength range of about 0.6 micrometers and greater.

15. The thermal measurement system of claim 13, wherein the plurality of detectors comprises three or more detectors.

16. The thermal measurement system of claim 13, wherein the detectors are selected from the group consisting of indium-gallium-arsenide based detectors, silicon based detectors, extended indium-gallium-arsenide based detectors and lead-antimony based detectors.

17. The thermal measurement system of claim 13, wherein the optical and probe subsystem comprises a fiber optic cable or an assembly of lenses and mirrors.

18. The thermal measurement system of claim 13, further comprising an analog to digital signal conditioner configured to convert an analog signal from each of the detectors to a digital signal.

19. The thermal measurement system of claim 13, further comprising a processor configured to receive intensity data from each of the detectors, and determine a temperature profile of the object based on the intensity data.

20. The thermal measurement system of claim 13, further comprising a plurality of filters configured to selectively filter the radiation received by the detectors.

21. The thermal measurement system of claim 13, wherein the object is a rotating object.

22. The thermal measurement system of claim 21, wherein the rotating object comprises a gas turbine blade.

23. The thermal measurement system of claim 21, configured to sample radiation at a plurality of spots on the rotating object during a revolution of the object.

24. The thermal measurement system of claim 21, further comprising a processor configured to receive a plurality of signals from the detectors and to determine a two dimensional temperature map of the rotating object.