This book offers a step-by-step guide to the use of instruments for the sampling of airborne dust, fibers, gases and vapors in the workplace and shows how to measure the indices of heat, noise and light and assess the performance of ventilation systems. An introduction to radiation and biological hazards is also included. Simple examples are given where it is necessary to use mathematical equations. This book explains how far an untrained person can go in this field before calling in experienced, specialist, help.