Observing safety guidelines
4-3
Installation Manual 323-3221-291 Rel 1.0 Standard
Optical fibers
Optical fibers are either single or multiple strand. The following information
and precautions apply to all fibers.
Laser radiation
All Northern Telecom optical products and associated optical test sets use laser
sources that emit light energy into fiber cables. This energy is within the red
(visible) and infrared (invisible) regions of the electromagnetic spectrum.
Laser products are subject to federal regulations, state or provincial
regulations, and local practices. Regulation 21CFR 1040 of the U.S. Bureau of
Radiological Health requires manufacturers to certify each laser product as
Class I, II, III, or IV depending on the characteristics of the laser radiation
emitted. In terms of health and safety, Class I products present the least hazard
(none at all), while class IV products present the greatest hazard.
During testing and maintenance, some procedures require the handling of
optical fibers and transmitters with the dust caps removed. Under these
circumstances, laser radiation within the limits of Class IIIb might be present.
This level of radiation is of sufficient magnitude to cause injury to personnel
and caution must therefore be exercised to avoid exposure. This precaution
applies to any point in the system where the laser signal can be accessed (for
example, at the optical connectors on the front of DV-OC3 units).
Bending optical fibers
There is a risk of damaging optical fibers if they are bent too much. A
minimum bending diameter of 76 mm (3 in.) is recommended. In addition, all
optical connections to optical units should only be finger-tightened.
Handling optical fibers
When working with optical fibers, you must observe the following
precautions:
•
Wear safety glasses when installing optical fibers.
•
Avoid direct exposure to fiber ends or optical connector ends where the
laser signal can be accessed.
All Northern Telecom S/DMS transmission
products comply with 21 CFR 1040, Chapter 1,
subchapter J as a Class I laser product as set forth
by the U.S. Bureau of Radiological Health. These
regulations ensure that there are no personnel
Avoid direct exposure to
beam. Invisible light can
blind. Keep all optical
connectors capped.
hazards from the laser transmitter when the system is in its operating
configuration. A label similar to this is located on all optical interface packs,
near the optical connector.
Caution
