3com 5000 Manuel Complémentaire

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3Com Router Safety, Regulatory, and Compliance Information 
20 
 
Diagram of wearing electrostatic protection wrist strap  
Laser 
The laser hazard level of this equipment is Class
 1
 
  Warning: 
When performing installation and maintenance operations of optical fibers, you should not stand 
close to, or look into the optical fiber outlet directly with unaided eyes.
 
 
General Laser Information 
Laser transceiver/ transmitter are used in optical transmission system and associated test 
instruments. The wavelength of the laser is above 780nm, and lower than 1600nm. Because the 
laser being transmitted through the optical fiber produces a small beam of light, it has very high 
power density and is invisible to human eyes. When a beam of light enters the eye, retinal may 
be burned. 
The damage mechanism at the wavelengths used in telecommunications is thermal in origin i.e., 
damage caused by heating. Therefore, a specific amount of energy is required for a definite time 
to heat an area of retinal tissue. 
Lasers used in lightwave systems have a larger beam divergence, typically 10 to 20 degrees. 
Inadvertently viewing an un-terminated fiber or damaged fiber with the unaided eye at distances 
greater than 150 mm (6 inches) will normally not cause eye injury. However, damage may occur if 
an optical instrument such as a microscope, magnifying glass or eye loupe is used to view the 
energized fiber end. 
In its normal operating mode, a lightwave system is totally enclosed and presents no risk of eye 
injury. Additional safety is achieved by the implementation of an Automatic Laser Shut-down 
(ALS) of the system. The ALS, however, can be applied for bi-directional transmission only. If the 
receiver side does not detect the laser from the transmission side, it will give the transmission 
side a signal, so the ALS will shutdown the laser emission in less than 100ms.