inspectors are checking defects in welded steel h-beam add joint with process ultrasonic testing (ut)

accessories add architecture assembly checking construction control defect defects destructive equipment experience factory frequency h-beam hand helmet industrial industry inspection inspector inspectors iron job joint machine material metal non-dest non-destructive object occupation people process professional protection quality repair safety skills steel structure surface technical technician technology testing testingndt texture tools ultrasonic welded welder welding work worker workshop