Radiation of Arc and Its Application in GTA Welding Measurement and Testing

The arc plasma radiation of gas tungsten arc welding (GTAW) is studied in this paper with the application of Avaspec-2048FT optical fiber digital spectrometer. The spectrum distribution from 200 nm to 1000 nm is analyzed. The result showed that different condition of the welding can provide spectrum with different radiation. The radiation in different frequency is dominant by spectral line of different element. The radiation intensity in the chosen frequency band is closely related to the stability of the arc. Furthermore, in order to detect the defect and disturbance of the process of welding, an in-situ sensing system with dual channel is developed with narrow-band filters. The radiation in visible and infra is collected with the sensor. The system can provide characteristic signal of welding trails with different disturbance factors.