This welding curriculum guide treats two topics in detail: the care of tungsten electrodes and the entire concept of contamination control and the hafnium electrode and its importance in dual-air cutting systems that use compressed shop air for plasma arc cutting activities. The guide contains three units of instruction that cover the following topics: orientation and safety; equipment, applications, and techniques; and plasma arc cutting. Each instructional unit includes some or all of the following basic components of a unit of instruction: objective sheet, suggested activities, answers to assignment sheets, answers to written test, written test, unit evaluation form, teacher supplements, transparency masters, information sheet, student supplements, assignment sheets, and job sheets. A glossary of technical terms is also included. The unit components focus on measurable and observable learning outcomes and are designed for use in more than one lesson or class period. This teacher edition also contains the following information: use of the publication; tools, materials, and equipment list; competency profile; instructional/task analysis; academic and workplace skill classifications and definitions; related academic and workplace skills list; and reference list. (KC)