A welding system using a purge plug for data acquisition. In one example, a purge plug includes purge plug component having a sealing structure. The sealing structure is configured to abut a surface of a hollow device and to form a seal between the sealing structure and the hollow device. The purge plug also includes a sensor at least partly disposed in the purge plug component, the sealing structure, or some combination thereof. The purge plug component is configured to be disposed on a workpiece having the hollow device to purge an undesired gas from the workpiece.