This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on operating high-volume air samplers. Following guidelines for students and instructors and an introduction that explains what the student will learn are three lessons: (1) disassembling the high-volume sampler, naming and identifying its major components, and explaining the purpose or function of each component; (2) operating the sampler, inspecting it for defects, and performing routine maintenance; and (3) plotting a calibration curve for a field-type rotameter. Each lesson contains objectives, recommended methods and locations for practice, performance criteria, equipment and supplies to perform a task, detailed step-by-step instructions for learning a task, and performance exercises. Performance tests cover subject matter of each lesson. (CT)