ISO/TC 190/SC 3/WG 14 - Physical methods

This document specifies an instrumental method for the routine determination of pH within the range pH 2 to pH 12 using a glass electrode in a 1:5 (volume fraction) suspension of soil, sludge and treated biowaste in either water (pH in H2O), in 1 mol/l potassium chloride solution (pH in KCl) or in 0,01 mol/l calcium chloride solution (pH in CaCl2). This document is applicable to all types of air-dried soil and treated biowaste samples. NOTE For example, pretreated in accordance with ISO 11464 or EN 16179 or EN 15002.

This document specifies a basic method of determining the particle size distribution applicable to a wide range of mineral soil materials, including the mineral fraction of organic soils. It also offers procedures to deal with the less common soils mentioned in the introduction. This document has been developed largely for use in the field of environmental science, and its use in geotechnical investigations is something for which professional advice might be required. A major objective of this document is the determination of enough size fractions to enable the construction of a reliable particle-size-distribution curve. This document does not apply to the determination of the particle size distribution of the organic components of soil, i.e. the more or less fragile, partially decomposed, remains of plants and animals. It is also realized that the chemical pre-treatments and mechanical handling stages in this document could cause disintegration of weakly cohesive particles that, from field inspection, might be regarded as primary particles, even though such primary particles could be better described as aggregates. If such disintegration is undesirable, then this document is not used for the determination of the particle size distribution of such weakly cohesive materials.

This document specifies laboratory methods for determination of the soil water-retention characteristic. This document applies only to measurements of the drying or desorption curve. Four methods are described to cover the complete range of soil water pressures as follows: a) method using sand, kaolin or ceramic suction tables for determination of matric pressures from 0 kPa to −50 kPa; b) method using a porous plate and burette apparatus for determination of matric pressures from 0 kPa to −20 kPa; c) method using a pressurized gas and a pressure plate extractor for determination of matric pressures from −5 kPa to −1 500 kPa; d) method using a pressurized gas and pressure membrane cells for determination of matric pressures from −33 kPa to −1 500 kPa. Guidelines are given to select the most suitable method in a particular case.

This document specifies a method for the determination of cation exchange capacity (CEC) and the content of exchangeable cations (Al, Ca, Fe, K, Mg Mn, Na) in soils using a hexamminecobalt(III)chloride solution as extractant. For soils containing calcium carbonate a calcite saturated hexamminecobalt(III)chloride solution is specified particularly for determination of exchangeable Ca. This document is applicable to all types of air-dry soil samples which have been prepared according to ISO 11464.

This document specifies a method for the determination of the cation exchange capacity (CEC) at the pH of the soil and for the determination of the content of exchangeable sodium, potassium, calcium and magnesium in soil. This document is applicable to all types of air-dried soil samples. ISO 11464 can be used for pre-treatment.

ISO 14254:2018 specifies a method for the determination of exchangeable acidity in barium chloride extracts of soil samples obtained according to ISO 11260. The procedure described herein mainly concerns the determination of total exchangeable acidity by means of a fixed pH end point titration. Two additional and optional procedures are given, describing respectively, determinations of free H+ acidity and aluminium in the extracts. ISO 14254:2018 is applicable to all types of air dry soil samples.

ISO 11508:2017 specifies two methods for the determination of particle density of soils calculated from the mass and the volume of soil particles. The first method (4.1) is applicable to fine soil (2 mm diameter). The particle density can be used for the calculation of the proportion of solids and of the porosity of soil layers in combination with the procedure given in ISO 11272.

ISO 11272:2017 specifies three methods for the determination of dry bulk density of soils calculated from the mass and the volume of a soil sample. The methods involve drying and weighing a soil sample, the volume of which is either known [core method (see 4.1)] or determined [excavation method (see 4.2) and clod method (see 4.4)].

This International Standard specifies the treatments for the measurement of the stability of soil aggregates. It can be applied to a wide range of materials originating mainly from the tilled horizons of cultivated soils. It can, however, also apply to any soil profile horizon, whether it is cultivated or not. Aggregates ranging from 3 mm to 5 mm are measured. However, the presence of gravel in the 2 mm to 5 mm fraction can distort the results. If the percentage of gravel is between 10 % and 40 %, the > 2 mm fraction of the gravel obtained from the tests should be washed and a mean weighted diameter (MWD, see 6.1) calculated with and without gravel. If the percentage of gravel is > 40 %, the structural stability tests are not significant. The method does not apply to unstructured materials, as they are not sufficiently cohesive to form millimetric aggregates.

Specifies a method for the determination of the potential cation exchange capacity (CEC) of soil buffered at pH = 8,1 and of the determination of the content of exchangeable sodium, potassium, calcium and magnesium in soil. Applicable to all types of air-dried soil samples.

Specifies procedures for the preparation of water and acid extracts of air-dried soils and soil-like materials. The sulfate content of these extracts is determined by a gravimetric method in which barium chloride is added to the water or acid extract and the precipitate of barium sulfate is dried and weighed. The sulfate content is then calculated from the mass of the material used in the analysis and the mass of barium sulfate precipitated. Applicable to all types of air-dried soils.

Specifies a method for the determination of carbonate content in soil samples. Applicable to all types of air-dried soil samples.

Specifies an instrumental method for the routine determination of the specific electrical conductivity in an aqueous extract of soil. The determination is carried out to obtain an indication of the content of water-soluble electrolytes in a soil.

The method specified can be applied to all types of soil samples. Different procedures are specified for air-dried soil samples, e.g. samples pretreated according to ISO 11464, and for field-moist soil samples. Its principle is drying soil samples to constant mass at 105 °C and using the difference in mass of an amount of soil before and after the drying procedure to calculate the dry matter and water contents on a mass basis. For the determination of soil water content on a volume basis, refer to ISO 11461.

ISO 10390:2005 specifies an instrumental method for the routine determination of pH using a glass electrode in a 1:5 (volume fraction) suspension of soil in water (pH in H2O), in 1 mol/l potassium chloride solution (pH in KCl) or in 0,01 mol/l calcium chloride solution (pH in CaCl2). ISO 10390:2005 is applicable to all types of air-dried soil samples, for example pretreated in accordance with ISO 11464.

ISO 11271:2002 specifies a field method for the determination of soil redox potential (Eh). NOTE The electrochemical measurement of redox potential described here is possible only if the relevant soil horizon has a moisture status defined as fresh or wetter according to the classes presented in annex D.