Method and apparatus for measuring weld penetration in an arc welding process

摘要

The penetration in an arc welding process is measured in real time by monitoring the natural frequency of oscillation of the weld pool. Spatial oscillations are induced in the weld pool by modulating either the shielding gas or the welding current at a plurality of different frequencies, and the light reflected from the pool at a non-specular angle is sensed and processed to determine the natural frequency of oscillation. Both pulse and swept frequency modulations are employed for excitation of the weld pool.