How is NDT used in Welding?
Weld joints can be tested by different tests in Non Destructive testing methods. The most common NDT methods to check welds are Visual testing, Liquid Penetrant testing, Magnetic Particle testing, Ultrasonic, and Radiography testing. Weld discontinuities are identified in the process of welding and we can perform high quality inspection in-between the whole welding process.
How is visual testing (VT) or visual inspection done on welding?
Visual testing should be the first non-destructive test method applied to an item in order to locate surface discontinues in most materials. Subsurface discontinuities can also be detected in translucent materials. Primarily, VT can be performed directly or indirectly. Both performance requirements are different. In the case of direct visual inspection, the component to be inspected is tested by an inspector. Testing, analysis and assessment are carried out by a single person. The direct visual inspection can be carried out with tools such as boroscopes, welding gauge, magnifier, caliper, scale and adequate lumination to find out discontinuities in welding as well as base metal. In indirect visual inspection, the area to be inspected is captured by a camera and displayed on a monitor. The test image can be subjected to further work steps. Nowadays, the trend is towards indirect visual inspection, as the use of camera technology offers more possibilities and leads to more efficient interruption of the production process.
How can I get certified for VT testing on welding?
One can get certified in VT from a Nondestructive testing institute, with proper training in theoretical knowledge, practical and theory examination. A Level III trainer can get you ASNT SNT TC 1A certification.