I.E.C. <br/><br/>
IEC: 61241-3, Ed.1-1997; Electrical apparatus for use in the presence of combustible dust- Part 3: Classification of areas where combustible dusts are or may be present. 

 - 1st 
 - Geneva  IEC  1997 
 - 41 
<br/><br/><label>Universal Decimal Class. No.: </label> /