Читать книгу Patty's Industrial Hygiene, Physical and Biological Agents - Группа авторов - Страница 88

For lasers where the direct beam and potential reflections are very limited, the concept of a nominal hazard zone (NHZ) is particularly useful. Control measures are only required within the defined NHZ for the laser operation. This may occur where the emitted beam is close to the AEL for Class 1, or as is more likely, when the beam is highly diverging within the work zone. A beam can rapidly diverge if beyond the focal point of the laser beam (e.g. for a laser welder or cutting beam), or the beam diverges rapidly from an optical fiber tip.