| jib crane quality supervision: Use ultrasonic to detect its defects, this is suitable for detection of kinds of metal materials, the internal defect. It is often used for pipe, plate, bar and weld; The test is fast, low cost, and wide application. X ray, Y ray or neutron ray test material's discontinuity, and show the image on recording medium to inspect its
inside defect. This testing is direct but expensive. Using magnetic leakage and appropriate test to find the discontinuity on specimen surface and near surface . In order to ensure that the quality of coating, the coating film performance testing mainly include the mechanical
properties (such as thickness, adhesion, gloss, etc.) and special properties (such as corrosion resistance, oil resistance, acid resistance, etc.). The test instrument include: coating thickness tester, tester, the adhesion tester, film griding instrument, etc. | 
