It is a device which detect the faults in nut and bolt welding such as nut mis-aligned, bad nut projection, incorrect nut, reverse feed, fallen nut, no workpiece, loose tip, workpiece mis-aligned, nut missing, no welding, nut overlapped, bolt length incorrect, etc before welding, and check if welding penetration is good or not after welding.

1. Weld stop function detecting abnormal nut and bolt
2. Pre setting the tolerance of standard value and displaying measured value in digital
3. Detecting bad weld penetration after welding
4. Interfacing with welding robot
5. Displaying error code in case of NG
6. Measuring and non-measuring mode
7. One cycle welding possible when the nuts of a kind are welded at one or several workpiece in different welding condition because of measuring each weld spot according to pre-set 15 welding schedules