Level I - Programmed Instruction Handbooks 

This entry-level material is designed as self-study instruction with quizzes
at the end of each chapter to reinforce learning. 
The "Introduction to NDT" book (PI-1) should be read prior to starting
any of the other books in the series.  Typically, it takes about 10-12
hours to complete each volume of Programmed Instruction (PI) text. 
Written examinations suitable for Level I-II qualifications are included
in the PI series.