PM-800-GL INSTRUCTION MANUAL
9
Class 2M
A Class 2M laser is safe because of the blink reflex if not viewed through optical
instruments. As with class 1M, this applies to laser beams with a large diameter or large
divergence, for which the amount of light passing through the pupil cannot exceed the
limits for class 2.
Class 3R
A Class 3R laser is considered safe if handled carefully, with restricted beam viewing. With
a class 3R laser, the MPE can be exceeded, but with a low risk of injury. Visible continuous
lasers in Class 3R are limited to 5 mW. For other wavelengths and for pulsed lasers, other
limits apply.
Class 3B
A Class 3B laser is hazardous if the eye is exposed directly, but diffuse reflections such as
from paper or other matte surfaces are not harmful. Continuous lasers in the wavelength
range from 315 nm to far infrared are limited to 0.5 W. For pulsed lasers between 400 and
700 nm, the limit is 30 mJ. Other limits apply to other wavelengths and to ultrashort
pulsed lasers. Protective eyewear is typically required where direct viewing of a class 3B
laser beam may occur. Class-3B lasers must be equipped with a key switch and a safety
interlock.
Class 4
Class 4 lasers include all lasers with beam power greater than class 3B. In addition to
posing significant eye hazards, with potentially devastating and permanent eye damage as
a result of direct beam viewing, diffuse reflections are also harmful to the eyes within the
distance called the Nominal Hazard Zone. Class 4 lasers are also able to cut or burn skin.
In addition, these lasers may ignite combustible materials, and thus represent a fire risk, in
some cases. Class 4 lasers must be equipped with a key switch and a safety interlock.