ASTM International

Standard Test Method for Pore Water Extraction and Determination of the Soluble Salt Content of Soils by Refractometer
 N D4542

Annotation

These test methods cover a rapid procedure for squeezing pore water from finegrained soils for the purpose of determining the amount of soluble salts present in the extracted pore water.

These test methods were developed for soils having a water content equal to or greater than approximately 14 %, for example, marine soils. An extensive summary of procedures for extracting pore water from soils has been presented by Kriukov and Manheim (1).2

These test methods are not generally applicable for determining the soluble salt content of the pore water extracted from coarse-grained soils, such as clean sands and gravels.

Test Method A provides a procedure using a refractometer with a refraction index scale; Test Method B provides a procedure using a refractometer with a parts per thousand (ppt) scale.

Units—The values stated in SI units are to be regarded as the standard.

All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 unless superseded by these test methods.

The procedures used to specify how data are collected/ recorded and calculated in the standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of these test methods to consider significant digits used in analysis methods for engineering data.