Method for an IR-radiation—based temperature measurement and IR-radiation—based temperature measuring device

• US 8,368,021 B2
• Filed: 03/28/2011
• Issued: 02/05/2013
• Est. Priority Date: 03/27/2010
• Status: Active Grant

• Current Assignee: Testo AG
• Original Assignee: Testo AG
• Inventors: Stratmann, Martin, Auer, Daniel, Zahn, Patrick, Messerschmid, Andreas, Hinkel, Sabine
• Primary Examiner(s): Kim, Kiho
• Application Number:
  US13/073,147
• Publication Number:
  US 20110235918A1
• Time in Patent Office: 680 Days
• Field of Search: 250330-335, 2503361-3362, 2503381-3385, 25033901-33915, 250/340, 2503411-3418
• US Class Current: 250/330
• CPC Class Codes: G01J 2005/0074 having separate detection of emissivity
• CPC Class Codes: G01J 2005/0077 Imaging
• 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 5/07 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: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0859 Sighting arrangements, e.g. cameras
• CPC Class Codes: G01J 5/53 Reference sources, e.g. standard lamps; Black bodies

Abstract

In a temperature measuring device (1) an IR-radiation detector (2) and a reference element (3) are provided, connected to a surface (6) of an object (7) in a heat-conducting fashion, with a first area (4) with high emissivity and a second area (5) with high reflectivity formed at the reference element (3), and the IR-radiation detector (2) is equipped for a separate detection of IR-radiation (9, 10, 11) from the first and second areas (4, 5) and a surface area (12) of the object (7). A computer (13) in the IR-radiation detector (2) is equipped to deduct a temperature measurement for the object (7), corrected for emissions and reflections from the detected IR-radiations (9, 10, 11).

Claims

1. A method for an IR-radiation-based temperature measurement in an object (7), comprising contacting the object (7) with a reference element (3) in a heat-conducting fashion, with the reference element (3) having a surface comprising a first area (4) and a second area (5), with the first area (4) having a higher emissivity than the second area, and the second area (5) having a higher reflectivity than the first area (4), separately detecting a first IR-radiation (9) emitted by the first area (4) of the reference element (3), a second IR-radiation (10) emitted by the second area (5) of the reference element (3), and a third IR-radiation (11) emitted by a surface area (12) of the object (7), determining at least one measurement each from the IR-radiations (9, 10, 11) detected, and determining an emissivity of the surface area (12) as well as a portion of the reflected IR-radiation of the object (7) from the measurements, and at least one of the first area (4) or the second area (5) of the reference element (3) can be identified with an electronic image processor (19) with an algorithm for detecting at least one of patterns or features in a recorded image (15, 17).

2. The method according to claim 1, wherein a temperature of the object (7) is determined from the measurement of the first IR-radiation (9), corrected by at least one of an emission coefficient or the portion reflected by the environment.

3. The method according to claim 1, wherein the first, second and third IR-radiations (9, 10, 11) are detected by recording at least one of a thermal image (15) or recording a VIS-image (17) corresponding to the thermal image (15) in a visible spectral range.

4. The method according to claim 3, wherein at least one of the thermal image (15) or the VIS-image (17) are rectified prior to further processing, and corresponding ones of the first area, the second area and the surface area (4, 5, 12) are determined in the VIS-image (17) and the thermal image (15).

5. The method according to claim 1, wherein prior to use the reference element (3) is provided with a marker (18) for defining a feature, the marker (18) is identified and localized with an electronic image processor (19) in a recorded image (15, 17), the IR-radiation (9, 10) to be detected from at least one of the first area (4) or the second area (5) is selected in reference to the identified and localized marker (18).

6. The method according to claim 1, wherein prior to detecting the IR-radiations (9, 10, 11) a scope is aligned to at least one of the surface area (12) of the object (7) or the reference element (3).

7. An IR-radiation based temperature measuring device (1), comprising an IR-radiation detector (2) and a reference element (3), the reference element (3) has a surface comprises a first area (4) and a second area (5), the first area (4) having a higher emissivity than the second area (5), and the second area (5) having a higher reflectivity than the first area (4), an IR-detector unit (8) is provide, by which IR-radiation (9, 10, 11), respectively emitted by the first area (4) and the second area (5) of the reference element (3) applied to the object (7) and by a surface area (12) of the object (7) is separately recorded and evaluated, a measuring device that determines at least one measurement each from the detected IR-radiations (9, 10, 11), and a computer (13) equipped to determine an emissivity of the surface area (12) and a portion of the IR-radiation reflected by the environment of the object (7) using measurements determined, and an image processor (19) is provided for identifying and localizing a marker (18) applied on a reference element (3) and the marker (18) defines a feature.

8. The temperature measuring device (1) according to claim 7, further comprising at least one of a VIS-camera (16) adapted to record a VIS-image (17) or an image processor (19) to rectify at least one of a recorded thermal image (15) or a recorded VIS-image (17).

9. The temperature measuring device (1) according to claim 7, wherein the marker (18) is embodied invisible in an infrared spectral range.

10. The temperature measuring device (7) according to claim 7, wherein selection means are provided, which are adapted to manually or automatically select IR-radiation (9, 10) to be detected from at least one of the first area (4) or the second area (5) in reference to the identified and localized marker (18).

11. The temperature measuring device (7) according to claim 10, wherein the selection means are adapted to select IR-sensors in an IR-sensor field equivalent to at least one of the first area (4) or the second area (5), and at least one of a relative image position of the second area (4) or the second area (5) is adapted to be stored or provided in reference to the identified and localized marker (18).