Filter
Top Products
INTRINSICALLY SAFE CLASSIFICATION
56
Classification of Hazardous Areas (Division)
Hazardous areas are classified as Division 1 or 2 as shown below.
Since a Division 1 area is considered most hazardous, a transceiver
approved for a specific Division 1 atmosphere can also be used in the
same Division 2 atmosphere. The intrinsically safe rating applies to
Division 1 areas and the nonincendive rating applies to Division 2 areas.
Class I and II Materials (Gases, Vapors, and Dusts)
Division Area
1 An area where there is or could be an explosive atmosphere
most of the time in normal operations.
2 An area where an explosive atmosphere exists only as a result
of a fault (something going wrong).
Class III Materials (Fibers or Flyings)
Division Area
1 An area in which easily ignitable fibers or materials producing
combustible flyings are handled, manufactured, or used.
2 An area in which easily ignitable fibers are stored or handled.
An exception is in process of manufacture.
Classification of Atmospheres (Class/Group)
For the purposes of testing and approval, various atmospheric mix-
tures have been grouped on the basis of their hazardous characteristics.
Equipment is approved for a class of material and also for the specific
group of gas, vapor, or dust in that class. Class I materials include gases
and vapors, Class II materials include combustible dusts, and Class III
materials include ignitable fibers or flyings. The typical hazardous mate-
rials in each group and class are shown in the following table.