Coating Thickness Measurement

Coating thickness measurement is performed to evaluate whether the coating sufficiently fulfills its protective or aesthetic function. The thickness of coatings, especially those made to provide corrosion resistance, reduce wear, provide electrical insulation and add aesthetic features, is critical to their performance.

Objectives of Coating Thickness Measurement:

Providing Corrosion Resistance: If metal surfaces need to be coated with a protective layer against corrosion, the coating thickness should be sufficient to provide this protection.

Abrasion Resistance: As the coating thickness increases on surfaces that will be exposed to abrasion, the life of the coating is extended and the surface is protected for a longer time.

Electrical Insulation or Conductivity: In some applications, a certain thickness is required to provide electrical conductivity or insulation.

Aesthetic Quality and Surface Appearance: It is important to apply paint or other decorative coatings homogeneously and in sufficient thickness to achieve the desired aesthetic result.

How to Measure Coating Thickness:

Magnetic Thickness Measurement Devices: Used to measure the thickness of paint or metal coatings on ferromagnetic surfaces.

Ultrasonic Measurement: Measurements can be made using ultrasonic waves, especially in thin and multi-layer coatings.

Eddy Current Method: Used to measure the thickness of non-conductive coatings on conductive surfaces.

Microscopic Section Examination: When more precise measurement is required, the coating is examined under a microscope and the thickness is measured.

Evaluation Criteria: The coating thickness is evaluated by comparing it with the minimum and maximum thickness ranges determined by the relevant standard (such as ISO 2178 or ASTM D7091) or design requirements. Coatings that are outside the tolerance range may provide insufficient protection or may cause problems such as excessively thick coating peeling. Therefore, coating thickness measurements are an important part of quality control processes.