Thermal imager that analyzes temperature measurement calculation accuracy

Patent metadata

Field	Value
Publication number	US-10965889-B2
Application number	US-201214127638-A
Country	US
Kind code	B2
Filing date	Jun 20, 2012
Priority date	Jun 20, 2011
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

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.

First claim

What is claimed is:

1. A method of determining whether an object of interest can have its temperature measurement accurately calculated by a thermal imaging camera comprising:
a) calculating a measurement instantaneous field of view (IFOV) of the camera and displaying the calculated measurement IFOV on a display of the camera as a graphical box such that the linear dimensions of the graphical box correspond to the size of the calculated measurement IFOV in linear units and represent the size of a smallest detail for which an accurate temperature can be calculated;
b) registering the graphical box with the object of interest on the display; and
c) determining whether or not a reliable temperature measurement of the object of interest can be made by determining whether the thermal image of the object of interest fills the graphical box thereby indicating that the size of object of interest is at least the size of the measurement IFOV and that a reliable temperature measurement 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 instantaneous field of view (IFOV) in linear units, the measurement IFOV corresponding to the linear dimensions of a smallest detail for which an accurate temperature can be calculated and being based on the determined distance between the camera and the object of interest; 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 non-transitory computer-readable medium comprising executable instructions for causing a programmable processor to perform 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 instantaneous field of view (IFOV) on a display of the camera as a graphical box such that the linear dimensions of the graphical box correspond to the size of the calculated measurement IFOV in linear units and represent the size of a smallest detail for which an accurate temperature can be calculated; and
b) registering the graphical box with the image of the object of interest on the display.

7. 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 instantaneous field of view (IFOV) in linear units and display the calculated measurement IFOV in linear units on the display, the measurement IFOV corresponding to the linear dimensions of a smallest detail for which an accurate temperature can be calculated by the hand-held thermal imaging camera.

8. A camera according to claim 7 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.

9. A camera according to claim 7 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.

Assignees

• Stuart Michael D
• Pickett James T
• Fluke Corp

Inventors

• Stuart Michael D
• Pickett James T

Classifications

• G01J5/0265 Primary

  Handheld, portable (ear thermometers G01J5/049) · CPC title

• H04N23/23

  from thermal infrared radiation · CPC title

• G01J5/025 Primary

  Interfacing a pyrometer to an external device or network; User interface · CPC title

• G01J5/07

  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 title

• G01J5/089

  Physics · mapped topic