ÖNORM EN 872

This document describes a method for the determination of suspended solids in raw waters, waste waters and effluents by filtration through glass fibre filters. The lower limit of the determination is about 2 mg/l. No upper limit has been established. Water samples are not always stable which means that the content of suspended solids depends on storage time, means of transportation, pH value and other circumstances. Results obtained with unstable samples need to be interpreted with caution. Floating oil and other immiscible organic liquids will interfere (see Annex A). Samples containing more than about 1 000 mg/l of dissolved solids can require special treatment (8.6). NOTE 1 The result of the determination depends to some extent on the type of filter used (5.2). It is therefore recommended that the type of filter is specified. NOTE 2 The size distribution of particles in different samples can vary widely. Therefore there is no correlation between results obtained with filters of different pore width and no conversion factor can be given for the conversion of results obtained with one type of filter to another.