BS EN ISO 11844‑1:2020 pdf download.Corrosion of metals and alloys – Classification of low corrosivity of indoor atmospheres.
1 Scope
This document establishes a classification of low corrosivity of indoor atmospheres.
It specifies the reference metals for which a corrosion attack after a defined exposure period is used for determining corrosivity categories of indoor atmospheres of low corrosivity.
It defines corrosivity categories of indoor atmospheres according to corrosion attack on
standard specimens.
It indicates important parameters of indoor atmospheres that can serve as a basis for an estimation of indoor corrosivity.
The selection of a method for the determination of corrosion attack, description of standard specimens, exposure conditions and evaluation are given in ISO 11844‑2. The measurement of environmental parameters affecting indoor corrosivity is given in ISO 11844‑3.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1
climate
statistics of temperature, humidity, atmospheric pressure, wind, rainfall, and other meteorological
elements in a given location over a long period of time
[SOURCE: EN 15759‑1:2011, 3.1]
3.2
atmosphere
mixture of gases, aerosols and particles that surrounds a given material, object or structure
3.3
indoor atmosphere
environment [combined effect of climate (3.1) and atmosphere (3.2)] inside a box, a room or a building
4 Symbols and abbreviated terms
IC indoor corrosivity
r corr corrosion rate derived from mass‑loss measurement after an exposure of one year
r mi rate of mass increase after an exposure of one year
5 Classification of corrosivity
5.1 General
The corrosivity of indoor atmospheres can be classified either by a determination of the corrosion attack on standard specimens of selected standard metals as given in Clause 6 or, where this is not possible, by an estimation of corrosivity based on the knowledge of humidity, temperature and pollution conditions as described in Clause 7 and Annexes B, C and D.
6 Determination of indoor atmospheric corrosivity
The determination of corrosivity of indoor atmospheres is based on measurements of corrosion attack on standard specimens of five reference metals after an exposure for one year in accordance with ISO 11844‑2. From the mass loss or mass increase, the indoor corrosivity category for each metal is determined from Table 2.
In indoor environments when the all conditions (temperature, humidity, air pollutions) vary only in range of ±5 % from average value, the exposure period should be shorter, e.g. one month only. Preferably, this month should represent the most corrosive period of the year.
Metals complement each other in the classification of indoor corrosivity for a given environment.BS EN ISO 11844‑1 pdf download.