BS EN ISO 11844-1:2020 pdf free.Corrosion of metals and alloys – Classification of low corrosivity of indoor atmospheres.
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.Environmental characteristics are informative and allow assessment of specific corrosion effects with regard to individual metals and metallic coatings. The ISO 16000 series deals with indoor air measurements describing the sampling strategy, including the conditions to be observed for particular substances or groups of substances, such as the dependence of indoor air pollution concentrations on atmospheric humidity or temperature or other effects. ISO 16000-1:2004, Table A.1, summarizes the most important types of indoor environment and gives examples of the sources that can be encountered in them. The list is not, of course, fully comprehensive because of the large number of possibilities. ISO 16000-1:2004, Table B.1, shows the sources of indoor air pollutants and the most important substances emitted. ISO 16000-1:2004, Table C.1, lists substances frequently detected and their possible sources. The ISO 16000 series does not cover all indoor air  pollutants significant for indoor atmospheric corrosivity. Methods for the characterization and measurement of environmental parameters of indoor atmospheres are given in ISO 11844-3. This method of corrosivity estimation is, in many cases, oversimplified and can give misleading results. An estimation of corrosivity is based on: climatic influences Coutdoor situation including pollution);indoor microclimate influences; indoor gaseous and particle pollution. The corrosivity of an indoor atmosphere increases with higher humidity and depends on the type and level of pollution. Important characteristics are frequency of variation of relative humidity (RH] and temperature (T) in intervals, and frequency and time of condensation.An indoor environment is rarely static, since the concentration of any substance can be constantly altered by the strength of the source, human activity, ventilation rate, external or internal climatic conditions, chemical reactions and possible sinks (e.g. sorption by surfaces and furnishings). In addition, the composition of indoor air can vary within and between rooms, and be less homogeneous than the outdoor air surrounding the building.BS EN ISO 11844-1 pdf download.