Industrial Communication Systems

12-6 Industrial Communication Systems

humidity in equatorial regions. In addition, many plants and facilities are dened as hazardous locations,

where

str

ict

req

uirements

app

ly

to any equ

ipment

ins

talled

in pot

entially

exp

losive

are

as.

National

regulations

for

equipment

operating

in

hazardous

areas

vary

from

country

to

country.

In

the

European

Union,

the

94/9/EC

ATEX

(ATmosphère EXplosible)

[94/9/EC]

directive

is

the

gov-

erning

document,

and

for

the

United

States

and

Canada,

the

North

American

Hazardous

Locations

Installation

Codes

(National

Electric

Code

for

the

United

States

and

the

Canadian

Electrical

Code

for

Canada)

dene

rules

and

reg