scope:

This European Standard (CSS99037) describes an instrumental method for routine determinations of specific electrical conductivity in aqueous extracts of sludge (fresh), treated biowaste (fresh) or soil (fresh or air-dry). Please note that soil improvers and growing media are not included in this standard. The EC determination is carried out to obtain an indication of the content of water-soluble electrolytes in the materials mentioned. The standard is based on ISO 11265. There is presently no international standard for sludge or treated biowaste. For practical reasons, for instance if there is a need to make strict comparisons with previous measurements, soils should generally be airdried. Air-drying can be used for all soils, except for those containing sulphidic minerals or volatile acids. In both cases fresh soil should be used to avoid either sulphide oxidation resulting in the formation of sulphuric acid, or volatilisation of low-molecular organic acids. Regarding sludge and treated biowaste, fresh samples are recommended. In these materials air-drying may introduce artefacts due to a stimulation of oxidation processes and should therefore be avoided.