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