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Thermo-Thickness-Detection
Large-area coating thickness measurement for industrial applications through the development of a multi-pulse-thermography
Project number: 21678 N
Project duration
From: 01.03.2021 To: 31.08.2023Description
Nowadays, coatings play a central role in many branches of the industry. Determining the coating thickness is an essential requirement –for quality control during production as well as for monitoring changes during the application. Among the available test methods for coating thickness measurement, thermography is a promising technology as it can be used inline in a non-destructive and non-contact manner. The combination technique of pulse and lock-in thermography developed in this research project, defined as multi-pulse thermography (MPT), combines the advantages of the two conventional thermography methods and allows a measurement of the thickness over a large area with a resolution in the one to two-digit micrometer range. For this purpose, the component is heated with several flashes of light and the surface temperature is measured simultaneously with an infrared camera. By calculating the phase image from the temperature data, differences in coating thickness can be visualized, although a calibration process is still necessary for the quantification of the coating thickness. The MPT has been successfully used on both metal and plastic components. The flexible adjustment of the pulse energy, the number of pulses and the pulse spacing allows an application-specific compromise to be found for measurement duration, thermal stress on the component and resolution. The MPT is relatively independent of geometric factors such as the orientation of the excitation unit and the infrared camera and therefore also enables a thickness measurement on more complex components without orthogonal alignment to the surface. Relevant results for different application scenarios and by using infrared cameras from different price categories are summarized in this research report.Contact person:
