For which one of the following types of tungsten electrodes can the electrode tip be balled (spherical)?
a. thoriated
b. zirconiated
c. lanthanated
d. ceriated
Question 2
The typical shielding gas for GTAW on deoxidized copper that is over 1/8 (3.2 mm) thick is _____.
a. helium
b. hydrogen
c. oxygen
d. argon