THERMAL IMAGER THAT ANALYZES TEMPERATURE MEASUREMENT CALCULATION ACCURACY

• US 20140176725A1
• Filed: 06/20/2012
• Published: 06/26/2014
• Est. Priority Date: 06/20/2011
• Status: Active Grant

• Current Assignee: Fluke Corporation (Fortive Corp.)
• Original Assignee: Fluke Corporation (Fortive Corp.)
• Inventors: Stuart, Michael D., Pickett, James T.
• Granted Patent: US 10,965,889 B2
• Time in Patent Office: Days
• US Class Current: 348/164
• 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 5/07 Arrangements for adjusting the solid angle of collected radiation, e.g. adjusting or orienting field of view, tracking position or encoding angular position optical collimating elements G01J5/0806
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

A method and computer program product for determining whether an object of interest can have its temperature measurement calculated by a thermal imaging camera. To do this, the measurement IFOV is converted into linear units. The measurement IFOV may be displayed on the display of the camera as a graphical indicator (100, 100′, 100″, 100′″) or a value. An object of interest can be registered with the graphical indicator (100, 100′, 100″, 100′″) or its dimension compared with the measurement IFOV and then it is determined whether the temperature measurement of the object can be acceptably calculated. Alternately, data obtained by a matrix of pixel elements may be analyzed to determine whether an accurate temperature can be calculated.

Claims

1. A method of determining whether an object of interest can have its temperature measurement accurately calculated by a thermal imaging camera comprising:

a) displaying a measurement IFOV of the camera on a display of the camera as a graphical box;

b) registering the graphical box with the object of interest on the display; and

c) determining whether the thermal image of the object of interest fills the graphical box thereby indicating a reliable temperature of the object of interest can be made.

2. A method of determining whether an object of interest can have its temperature measurement accurately calculated by a thermal imaging camera comprising:

a) determining a distance between the camera and the object of interest;

b) calculating a measurement IFOV in linear units; and

c) displaying the calculated measurement IFOV in linear units on the display of the camera to be viewable by a user of the camera.

3. The method of claim 2 wherein step (a) is performed by a laser rangefinder.

4. The method of claim 2 wherein step (a) is performed by the user of the camera entering the distance information on a data entry device of the camera.

5. The method of claim 2 further comprising d) determining whether the camera is an unsafe distance from the object of interest and, if so, e) generating an alarm that the camera is at an unsafe distance.

6. A computer program product, comprising a computer usable medium having a computer readable program code embodied therein, said computer readable program code adapted to be executed to implement a method for determining whether an object of interest can have its temperature measurement accurately calculated by a thermal imaging camera, said method comprising:

a) displaying a measurement IFOV on a display of the camera as a graphical box; and

b) registering the graphical box with the image of the object of interest on the display.

7. A method of determining whether an object of interest can have its temperature measurement accurately calculated by a thermal imaging camera comprising:

a) generating temperature data of an object of interest in the form of a pixel matrix comprised of multiple pixels; and

b) performing a statistical analysis on the data generated by the pixel matrix to determine uniformity of the data generated by the pixel matrix.

8. The method of claim 7 further comprising the step of generating a notification if the analysis performed in step (b) indicates that the data is not uniform.

9. The method of claim 7 further comprising the step of generating a notification if the analysis performed in step (b) indicates that the data is uniform.

10. The method of claim 7 further comprising the step of displaying an appropriate message on a display of the camera.

11. The method of claim 10 wherein the notification comprises an alarm.

12. The method of claim 10 wherein the notification comprises an audio recording telling the user of the camera to move closer to the object of interest in order to get an acceptable temperature measurement calculation and once the user has moved to a new distance from the object of interest, performing steps (a) through (d).

13. The method of claim 7 wherein step (b) includes

determining a minimum value of the data;

determining a maximum value of the data;

computing an arithmetic difference between the minimum and maximum values;

determining if the arithmetic difference exceeds a predetermined threshold;

if the arithmetic difference exceeds the predetermined value, generating an indication that the data is not usable as an accurate temperature.

14. The method of claim 7 wherein step (b) includes

computing an arithmetic average of the data;

determining if the difference between any of the data from each pixel and the average of the data exceeds a predetermined threshold;

if the difference determined in step (e) exceeds the threshold, generating an indication that the data is not usable as an accurate temperature.

15. A portable, hand-held thermal imaging camera comprising:

a lens assembly having an associated sensor for detecting thermal images of a target scene;

a display adapted to display at least a portion of the thermal image;

a processor programmed to calculate a measurement IFOV in linear units and display the calculated measurement IFOV in linear units on the display.

16. A camera according to claim 15 further comprising a distance measuring device for measuring the distance between the camera and the object of interest and providing that measurement to the processor in order for the processor to calculate the measurement IFOV in linear units.

17. A camera according to claim 15 further comprising an input device for entering data reflective of the distance between the camera and the object of interest and providing that data to the processor in order for the processor to calculate the measurement IFOV in linear units.

18. A portable, hand-held thermal imaging camera comprising:

a lens assembly having an associated sensor for detecting thermal images of a target scene;

a display adapted to display the thermal image;

a processor programmed to perform a statistical analysis on data generated by a pixel matrix to determine the uniformity of the data.

19. The camera of claim 18 wherein the processor is programmed to generate a notification based on the statistical analysis performed.

20. The method of claim 19 wherein the notification is an appropriate message displayed on the display of the camera.

21. The camera of claim 19 wherein the notification is an audio recording telling the user of the camera if an accurate temperature measurement can be made, and, if not, telling the user of the camera to move closer to the object of interest and once the user has moved to a new distance from the object of interest, the statistical analysis is performed again and a new notification is generated based on the statistical analysis performed.

22. The camera of claim 18 wherein the pixel matrix comprises three-by-three array of pixels.

23. The camera of claim 18 wherein the statistical analysis performed by the processor comprises:

determining a minimum value of the data;

determining a maximum value of the data;

computing an arithmetic difference between the minimum and maximum values;

determining if the arithmetic difference exceeds a predetermined threshold; and

if the arithmetic difference exceeds the predetermined value, generating an indication that the data is not usable as an accurate temperature.

24. The camera of claim 18 wherein the statistical analysis performed by the processor comprises:

computing an arithmetic average of the data;

determining if the difference between any of the data from each pixel and the average of the data exceeds a predetermined threshold;

if the difference determined exceeds the threshold, generating an indication that the data is not usable as an accurate temperature.