Purpose of coating thickness testing

What is the purpose of coating thickness testing?The anticorrosion coating of the steel structure is dominated by paint materials, and rubber, plastic and other materials may be used for special projects. The judgment of the anti-corrosion effect is generally based on the thickness of the coating. The anti-corrosion coating thickness test should be conducted after the coating is dried, and there should be no condensation on the surface of the component during the test; if there is a quality problem in the appearance of the component coating before testing, it should be repaired, and the coating thickness should be tested after repair.How to measure the coating thickness?

At present, the coating thickness testing methods mainly include the magnetic method, the eddy current method, and the supergene thickness measurement method. For specific testing methods, see "Technical Standards for On-site Testing of Steel Structures" (GB/T 50621-2010). When measuring, the maximum range of the coating thickness gauge is generally 1000-1500μm, the minimum resolution is usually 1-2μm, and the relative error of the indicated value should not be greater than 3%. The radius of curvature of the test component should meet the requirements of the instrument. When measuring the surface during bending time, the influence of the curvature on the test accuracy should be considered. The same component shall be tested at 5 points, and each point shall be tested at 3 measuring points 50mm apart. The coating at the measuring point should be well adhered to the steel. When using a paint thickness gauge, electromagnetic interference should be avoided.