Radiation Thermometer

• US 20090037135A1
• Filed: 02/06/2007
• Published: 02/05/2009
• Est. Priority Date: 02/06/2006
• Status: Active Grant

• Current Assignee: Land Instruments International Ltd. (Ametek Incorporated)
• Original Assignee: Land Instruments International Ltd. (Ametek Incorporated)
• Inventors: Metcalfe, Stuart Francis, Ridley, Ian Hamilton, Lyndon, Adrian John Masefield
• Granted Patent: US 8,042,997 B2
• Time in Patent Office: Days
• US Class Current: 702/134
• CPC Class Codes: G01J 5/02 Constructional details
• CPC Class Codes: G01J 5/025 Interfacing a pyrometer to an external device or network; User interface
• CPC Class Codes: G01J 5/0265 Handheld, portable ear thermometers G01J5/049
• CPC Class Codes: G01J 5/06 Arrangements for eliminating effects of disturbing radiation; Arrangements for compensating changes in sensitivity for adjusting of solid angle of collected radiation G01J5/07; means for wavelength selection G01J5/0801
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0802 Optical filters
• CPC Class Codes: G01J 5/0856 Slit arrangements
• CPC Class Codes: G01J 5/0859 Sighting arrangements, e.g. cameras
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices

Abstract

A radiation thermometer comprising a radiation detector and an optical input path arranged to direct radiation from an object of interest to the radiation detector is disclosed. The radiation detector is adapted to output a signal related to the radiation received from the object of interest, and a processor is adapted to generate temperature measurements from the signal. Filtering means are provided in the optical input path which are arranged to block radiation having a wavelength between approximately 0.92 and 0.98 microns.

Claims

1. A radiation thermometer comprising a radiation detector and an optical input path arranged to direct radiation from an object of interest to the radiation detector, the radiation detector adapted to output a signal related to the radiation received from the object of interest, and a processor adapted to generate temperature measurements from the signal, wherein filtering means are provided in the optical input path and which are arranged to block radiation having a wavelength between approximately 0.92 and 0.98 microns.

2. A radiation thermometer according to claim 1 wherein the filtering means are arranged to additionally block radiation having a wavelength less than approximately 0.85 microns.

3. A radiation thermometer according to claim 1 or claim 2 wherein the filtering means are arranged to additionally block radiation having a wavelength more than approximately 1.10 microns.

4. A radiation thermometer according to any of the preceding claims wherein the radiation detector is not sensitive to radiation having a wavelength more than approximately 1.10 microns.

5. A radiation thermometer according to any of claims 1 to 4 wherein the filtering means comprise one or more spectral filters.

6. A radiation thermometer according to any of the preceding claims further comprising an objective lens assembly having adjustable separation from a field stop fixed close to the detector, the objective lens assembly being disposed in the optical input path between the object of interest and the filtering means.

7. A radiation thermometer according to any of claims 1 to 6 further comprising a splitter assembly disposed in the optical input path between the object of interest and the filtering means, the splitter assembly adapted to direct a portion of the radiation from the object of interest along an optical viewing path.

8. A radiation thermometer according to claim 7 further comprising a visible-light viewing assembly disposed in the optical viewing path and arranged to generate a visible-light image of the object of interest.

9. A radiation thermometer according to claim 8 wherein the visible-light viewing assembly comprises means for viewing the visible-light image of the object of interest together with a graticule for defining a target area on the visible-light image.

10. A radiation thermometer according to any of the preceding claims further comprising a field-stop aperture disposed in the optical input path.

11. A radiation thermometer according to claim 10 when dependent on claim 9 wherein the field stop is adapted to pass only radiation emanating from the target area of the object of interest corresponding to the target area on the visible-light image defined by the graticule.

12. A radiation thermometer according to any of the preceding claims wherein the radiation detector is a semiconductor detector, the semiconductor preferably comprising silicon or InGaAs.

13. A radiation thermometer according to any of the preceding claims wherein the processor is adapted to generate temperature measurements in one or more of an instantaneous temperature mode, an average temperature mode, a peak-picking temperature mode and a valley-picking temperature mode.

14. A radiation thermometer according to any of the preceding claims further comprising a switch for controlling the operation of the processor.

15. A radiation thermometer according to claim 14 wherein the switch is operable between three positions, each position corresponding to a different command for operation of the processor.

16. A radiation thermometer according to any of the preceding claims further comprising a memory for storing the signal output by the detector or the temperature measurements generated by the processor.

17. A radiation thermometer according to any of the preceding claims further comprising an internal display, viewable by the visible-light viewing assembly, for displaying the temperature measurements generated by the processor.

18. A radiation thermometer according to any of the preceding claims further comprising an external display, viewable by a user, for displaying data including the temperature measurements generated by the processor.

19. A radiation thermometer according to claim 18 wherein the data displayed by the external display further includes one or more of a user-set parameter and control settings relating to the operation of the radiation thermometer.

20. A radiation thermometer according to any of the preceding claims further comprising a connector for a serial data connection, for communication with an external device.

21. A radiation thermometer according to any of the preceding claims further comprising a wireless data connection module for wireless communication with an external device.

22. A radiation thermometer according to claim 21 wherein the wireless data connection module supports the Bluetooth protocol.

23. A radiation thermometer according to claim 22 wherein the wireless data connection is adapted to transmit the temperature measurements generated by the processor to the external device.

24. A radiation thermometer according to claim 23 wherein the wireless data connection is further adapted to transmit at least one parameter used by the processor to generate the temperature measurements from the signal.

25. A radiation thermometer according to claim 24 where in the at least one parameter includes one or more of emissivity data, calibration settings and time constants.

26. A system for monitoring temperature comprising a central processing unit having a wireless data connection module and one or more radiation thermometers according to any of the claims 21 to 25 adapted to communicate with the central processing unit.

27. A system for monitoring temperature according to claim 26 wherein the central processing unit is adapted to perform data logging.

40. A method of monitoring temperature according to any of claims 28 to 39, using the radiation thermometer of claim 15, and further comprising:

initiating generating and sampling of the temperature signal by moving the switch from a first position to a second position,

when the switch is at the second position, generating and sampling the temperature signal according to one or more of an instantaneous temperature mode, an average temperature mode, a peak-picking temperature mode and a valley-picking temperature mode;

moving the switch from the second position to a third position; and

when the switch is at the third position, continuously transmitting temperature measurements generated according to the instantaneous temperature mode during at least a portion of the period for which the switch is at the third position, to an external device.

41. A method of monitoring temperature according to claim 40 wherein the temperature measurements are continuously transmitted for the whole duration of the period for which the switch is at the third position.

42. A method of monitoring temperature according to claim 40 wherein the temperature measurements are continuously transmitted for a predetermined duration.

43. A method of monitoring temperature according to claim 42 wherein the predetermined duration exceeds the period for which the switch is at the third position.

28. A method of monitoring temperature of a target using a radiation thermometer having a memory for storing data, comprising:

receiving radiation emitted by the target at the radiation thermometer;

generating a temperature signal derived from the received radiation;

sampling the temperature signal at predetermined intervals to produce a plurality of sample values;

recording each of the plurality of sample values in the memory; and

transmitting the stored plurality of sample values to an external device.

29. A method of monitoring temperature according to claim 28 wherein each of the plurality of sampled values is recorded in the memory before transmission to the external device.

30. A method of monitoring temperature according to claim 28 or claim 29 wherein the step of transmitting occurs after each of the plurality of sample values is produced.

31. A method of monitoring temperature according to any of claims 28 to 30 wherein the step of transmitting occurs after all of the plurality of sample values have been produced.

32. A method of monitoring temperature according to any of claims 28 to 31 further comprising recording at least some of the plurality of sample values in the external device.

33. A method of monitoring temperature according to claim 32 wherein sample values transmitted during a predetermined period are recorded by the external device.

34. A method of monitoring temperature according to claim 33 wherein the predetermined period is between 1 and 60 seconds, preferably about 30 seconds.

35. A method of monitoring temperature according to any of claims 28 to 34 wherein the duration of the predetermined intervals is 250 milliseconds or less, preferably approximately 30 milliseconds.

36. A method of monitoring temperature according to any of claims 28 to 35 wherein the transmitting is performed via a serial port connection between the radiation thermometer and the external device.

37. A method of monitoring temperature according to any of claims 28 to 35 wherein the transmitting is performed via a wireless connection between the radiation thermometer and the external device.

38. A method of monitoring temperature according to claim 37 wherein the wireless connection utilises the Bluetooth protocol.

39. A method of monitoring temperature according to any of claims 28 to 31 wherein the radiation thermometer is portable.