(Pollution Degree) EN 61010-1:2010 specifies 
pollution degrees and their requirements as 
follows. The GPP Series falls under degree 2. 
Pollution refers to “addition of foreign matter, 
solid, liquid, or gaseous (ionized gases), that 
may produce a reduction of dielectric strength 
or surface resistivity”. 
  Pollution degree 1: No pollution or only dry, 
non-conductive pollution occurs. The pollution 
has no influence. 
  Pollution degree 2: Normally only non-
conductive pollution occurs. Occasionally, 
however, a temporary conductivity caused by 
condensation must be expected. 
  Pollution degree 3: Conductive pollution 
occurs, or dry, non-conductive pollution occurs 
which becomes conductive due to condensation 
which is expected. In such conditions, 
equipment is normally protected against 
exposure to direct sunlight, precipitation, and 
full wind pressure, but neither temperature nor 
humidity is controlled.