Omron L User Manual page 179

Section 7
3. Definitions of Laser Classification
3-1 For Europe
Laser Product Classifications
EN
Class
Class 1
Class 2
Class 3A
Class 3B
Class 4
Note: Conditions for safe viewing of diffuse reflections for Class 3B visible lasers are: minimum viewing distance of 13
cm between screen and cornea and a maximum viewing time of 10 s. Other viewing conditions require a com-
parison of the diffuse reflection exposure with the MPE.
3-2 For U.S.A
Comparison of Classifications between FDA and ANSI
Class
Class I/1
Class IIa/2a
Class II/2
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User's Manual
Lasers which are safe under reasonably foreseeable conditions of operation.
Lasers emitting visible radiation in the wavelength range from 400 nm to 700 nm. Eye pro-
tection is normally afforded by aversion responses including the blink reflex.
Lasers which are safe for viewing with the unaided eye. For laser emitting in the wave-
length range from 400 nm to 700 nm, protection is afforded by aversion responses includ-
ing the blink reflex. For other wavelengths the hazard to the unaided eye is no greater than
for Class 1. Direct intrabeam viewing of Class 3A lasers with optical aides (e.g., binoculars,
telescopes, microscopes) may be hazardous.
Direct intrabeam viewing of these lasers is always hazardous. Viewing diffuse reflections is
normally safe (see note).
Lasers which are also capable of producing hazardous diffuse reflections. They may cause
skin injuries and could also constitute a fire hazard. Their use requires extreme caution.
FDA definition
Limits applicable to devices that have emis-
sions in the ultraviolet, visible, and infrared
spectra, and limits below which biological
hazards have not been established.
Limits applicable to products whose visible
emission does not exceed Class I limits for
emission durations of 1,000 seconds or less
and are not intended for viewing.
Limits applicable to products that have emis-
sions in the visible spectrum (400 to 710
nm) for emission durations in excess of 0.25
second, providing that emissions for other
durations and/or wavelengths do not exceed
the Class I limits. Class II products are con-
sidered hazardous for direct long-term ocu-
lar exposure.
Description
ANSI description
A Class 1 laser is considered to be incapa-
ble of producing damaging radiation levels
during operation and maintenance and is,
therefore, exempt from any control mea-
sures or other forms of surveillance.
Class 2 lasers are divided into two sub-
classes, 2 and 2a. A Class 2 laser emits in
the visible portion of the spectrum (0.4 to 0.7
µ
m) and eye protection is normally afforded
by the aversion response including the blink
reflex.