Non-destructive coating thickness measurement

Non-destructive coating thickness measurement is a method of determining the thickness of a coating on a substrate without damaging the material. This process is used in various industries such as automotive, aerospace, electronics manufacturing and many others where accurate control of coating thickness is critical.

The process is based on different physical principles, including magnetic induction, eddy current, ultrasound and X-rays. Each of these principles has its own advantages and disadvantages and is suitable for specific applications. In magnetic induction, a magnetic field is generated that penetrates through the coating and the substrate. The change in the magnetic field is measured and converted into a coating thickness.

In eddy current testing, a high-frequency electrical alternating current source is used to generate eddy currents in the material. The eddy currents react to the thickness of the coating and can be measured to draw conclusions about its thickness. Ultrasonic measurements send sound waves through the coating and measure the time it takes to travel from the ultrasonic transmitter to the receiver. The thickness of the coating influences the transit time of the sound waves and therefore enables the thickness of the coating to be determined.

X-rays are used to measure the material density by sending X-rays through the coating. The absorption of the rays depends on the thickness and density of the coating, which makes it possible to determine the thickness of the coating.

These methods provide a non-destructive way to accurately measure coating thickness, which is essential for quality assurance and process control in many industries.