METHOD FOR STUDYING THE SURFACE COMPOSITION OF PLANAR STRUCTURES

• US 20110085582A1
• Filed: 11/19/2008
• Published: 04/14/2011
• Est. Priority Date: 11/20/2007
• Status: Abandoned Application

• Current Assignee: Hubert Palfinger Technologies GmbH (Palfinger AG)
• Original Assignee: Plfinger Systems GmbH
• Inventors: Maier, Florian, Zagar, Bernhard
• Application Number:
  US12/734,700
• Publication Number:
  US 20110085582A1
• Time in Patent Office: Days
• US Class Current: 374/9
• CPC Class Codes: G01B 21/085 using thermal means
• CPC Class Codes: G01N 25/72 Investigating presence of flaws

Abstract

The invention relates to a method for studying the surface composition of planar structures (1), wherein specific surface areas are first heated continuously in a controlled way by a heat source (2), which is moved along the surface, and a temperature measurement is performed after a predetermined time, in order to determine the cooling behavior. High precision can be achieved in that the surface areas which are heated by the heat source (2) are detected at multiple moments by a thermal imaging camera (3), in order to prepare a temperature profile of individual surface points. Furthermore, the present invention relates to a device for performing the method.

Claims

1. A method for examining the surface composition of planar structures (1), in which specific surface areas are first heated continuously in a controlled way by a heat source (2) and temperature measurements are performed after a predetermined time in order to determine the cooling behavior, in that the surface areas which are heated by the heat source (2) are detected at multiple moments by a thermal imaging camera (3) in order to prepare a temperature profile of individual surface points, wherein the heat source is moved with a movement speed v over the surface, the thermal imaging camera (3) covers a length area of length s in the direction of movement, the time interval for performing the measurements with the thermal imaging camera (3) is t₀ in each case, and further the time interval t_o is less than 10%, preferably less than 5%, of the ratio of length s to the speed of movement v, i.e.

t₀<

0.1·

s/v,

preferably

t₀<

0.05·

s/v.

2. The method according to claim 1, wherein for evaluating the surface at least one characteristic cooling time constant τ

is calculated.

3. An apparatus for examining the surface composition of planar structures (1), comprising a heat source (2) and a measuring device (3) arranged as a thermal imaging camera (3) for detecting the surface temperature of the structure (1) which is connected with the device for moving the heat source (2) and which is arranged to repeatedly perform measurements of areas of the surface which are subjected to the heat source (2), including a device for moving the heat source (2) along the surface of the structure in order to cover several measuring areas, with the respective measuring areas overlapping, and the thermal imaging camera (3) has a refresh rate (f_rate) which is determined in such a way that the time interval for performing the measurements with the thermal imaging camera (3) is t₀ in each case, and further the time interval t₀ is less than 10%, preferably less than 5%, of the ratio of the length s to the speed of movement v, i.e.

t₀<

0.1·

s/v,

preferably

t₀<

0.05·

s/v.

4. The apparatus according to claim 3, wherein the heat source is at least one halogen lamp.

5. The apparatus according to claim 4, wherein the at least one halogen lamp is arranged in the manner of a rod.

6. The apparatus according to claim 5, wherein the heat source (2) is at least one infrared radiator.

7. The apparatus according to claim 3, wherein the thermal imaging camera (3) is an IR camera with a resolution of at least 240×

320 pixels.