NBN EN 12500 : 2000

Introduction
1 Scope
2 Normative references
3 Terms and definitions
      3.1 Corrosivity
      3.2 Corrosion likelihood
      3.3 Type of atmospheric environment
      3.4 Category of location
      3.5 Time of wetness
4 Classification of corrosivity of atmospheric
      environments
5 Determination of corrosivity categories
6 Estimation of corrosivity categories
      6.1 General
      6.2 Climatic influences
      6.3 Types of atmospheric environment
      6.4 Categories of location
             6.4.1 General
             6.4.2 Outdoor atmosphere
             6.4.3 Indoor atmosphere
Annex A (normative) Description of standard specimens and
                    exposure conditions for determination
                    of corrosivity categories
Annex B (normative) Chemical cleaning procedures for removal
                    of corrosion products (in accordance
                    with ISO 9226)
Annex C (informative) Correspondence between the mass loss
                      per unit surface area and the thickness
                      loss after 1 year exposure for the
                      corrosivity categories
Annex D (informative) Calculated time of wetness and selected
                      climatological characteristics of the
                      macroclimatic zones of the earth
Annex E (informative) Description of typical atmospheric
                      environments related to the estimation
                      of corrosivity categories
Bibliography

Specifies a classification system for corrosivity of atmospheric environments. Defines corrosivity categories of atmospheric environments accounting for ISO 9223; describes the determination of corrosivity assessing the mass loss of standard specimens after the first year of exposure; estimates the corrosivity of an environment based on knowledge of local conditions (or specific data that characterize them), where an experimental determination is not possible. The classification system contributes to the knowledge and comparison of corrosivity of atmospheric environments at different locations; the choice of materials and corrosion protection measures. Cannot determine corrosivity categories from exposure periods less or greater than the first year.