For the carbon dioxide welding torch, the inspection operation should be carried out continuously, when the magnetizing current passing, then applied magnetic powder, dry magnetic powder should be sprayed or spread, the particle size should be uniform, generally not less than 200 mesh sieve screening. Magnetic suspension should be poured slowly, pay attention to the amount. Application of fluorescent magnetic powder should be carried out in the dark, the UV detection light to open before checking for 5min, so that fluorescent powder issued a significant fluorescence. In order to prevent missed seizures, each weld generally requires two times of inspections, the direction of the magnetic lines should be generally vertical.
