🏗️ Particle size distribution of soils — sieving, hydrometer and pipette methods — PN-EN ISO 17892-4

Construction PN-EN ISO 17892-4

Overview

SCOPE (PKN card and clause 1 of ISO 17892-4:2016): laboratory determination of the particle size distribution of soil by sieving, by sedimentation or by a combination of both, as part of geotechnical investigations. Particle size distribution is one of the most important physical properties of soil — soil classification is based mainly on it, and many geotechnical and permeability properties depend on it. Coarse soils are usually tested by sieving, and fine-grained and mixed soils by a combination of sieving and sedimentation. The sieving method covers all uncemented soils with particles smaller than 125 mm; two sedimentation methods are described — the hydrometer and the pipette method. Note of the standard: this part meets the requirements for particle size determination in geotechnical investigations according to EN 1997-2.

WHICH METHOD TO CHOOSE (5.1): the method or combination of methods is specified before the test, and if it is not specified: • when there are less than about 10 % of particles smaller than 0.063 mm, sedimentation is usually not needed; • when the whole sample is smaller than 2 mm and there are less than about 10 % of particles larger than 0.063 mm, full sieving is usually not needed; • in the other cases sieving and sedimentation are carried out. The clause numbers in accreditation scopes therefore have a content: 5.2 is the sieving method, 5.3 — the hydrometer method, 5.4 — the pipette method, 5.5 — combined testing (table of contents of the standard). The notation "p. 5.2" [p. = clause] means sieving only, without the silt and clay fraction.

EQUIVALENT DIAMETER (definition 3.6): in sedimentation the particle size is an EQUIVALENT DIAMETER, calculated from Stokes' law assuming spherical particles — not a measured dimension. Hence the results below 0.063 mm from sedimentation and above it from sieving are two different measures combined into one curve.

REQUIREMENTS FOR EQUIPMENT AND REAGENTS (clause 4, text of the standard): • balance: for sieving and the hydrometer an accuracy of 0.01 g or 0.1 % of the mass weighed, for the pipette 0.001 g or 0.1 % — whichever is greater; • clock reading to 1 s, thermometer reading to 0.1 °C; • sieves according to ISO 3310-1 and ISO 3310-2; sieves of 63 mm, 20 mm, 6.3 mm, 2.0 mm, 0.63 mm, 0.20 mm and 0.063 mm are recommended — fraction boundaries according to ISO 14688-1; • glass hydrometer, streamlined, with a range of at least 0.9950–1.0300 g/ml and a scale division of 0.0005 g/ml or less; sedimentation cylinders with a 1000 ml mark, with a diameter at least twice that of the hydrometer bulb; • the temperature in the cylinders must not change during the test by more than 3 °C — otherwise a water bath with control; • pipette with a nominal volume of 2 % of the suspension volume, cylinders of at least 500 ml; • dispersing agent: for sieving sodium hexametaphosphate or tetrasodium diphosphate about 2 g/l; for sedimentation hexametaphosphate about 40 g/l or diphosphate about 20 g/l; the solutions are not used longer than one month after preparation. The standard points out that there is no single agent best for all soils; • hydrogen peroxide 20 % (V/V) for removing organic matter and hydrochloric acid 0.2 M ± 0.02 M for removing carbonates — optionally, according to Annex B.

STATUS (state of the PKN card and the ISO website on 25.09.2026). PN-EN ISO 17892-4:2017-01 — English-language version, publication 18-01-2017, 44 pages, KT 254 Geotechnics, ICS 13.080.20 and 93.020; it implements EN ISO 17892-4:2016 and ISO 17892-4:2016 [IDT]; the card has no "Withdrawn" header. ISO website: ISO 17892-4:2016 — edition 1, "last reviewed and confirmed in 2022". According to the foreword, ISO 17892-4:2016 replaced the technical specification ISO/TS 17892-4:2004 (with corrigendum Cor 1:2006). In the accreditation scopes one entry still cites "ISO/TS 17892-4:2009 p.5.2", and two put next to it "PKN-CEN ISO/TS 17892-4:2009" — the Polish edition of this specification, whose successor is the standard described here.

HOW ACCREDITATION SCOPES CITE THE STANDARD. Measurement of 25.09.2026 on the database of PL accreditation scopes (1310 laboratories with entries): 22 entries at 14 laboratories with the notation "PN-EN ISO 17892-4" — most often "PN-EN ISO 17892-4:2017-01" (16), with the clauses "p. 5.2" (2) and "p. 5.3" (2); in addition one entry with the ISO/TS specification alone. Object: ground (also "Gleba, grunty" [soil, ground], "Grunty, osady morskie" [ground, marine sediments], bottom sediments). Technique: sieving method (9) or hydrometer method (5). Declared ranges: "(0,063 – 63,0) mm", "(0 – 63,0) mm", "(0,000 – 0,063) mm", "(0,020 – 20,0) mm". The upper limit of 63 mm results from the laboratory's equipment — the standard covers sieving up to 125 mm.

THE KEY OF THE "LABORATORIES" TAB: "PN-EN ISO 17892-4" — 14 laboratories and 22 entries, without any foreign entries; it does not include the entry with the ISO/TS 17892-4:2009 specification alone (AB 1299).

WHAT WE DO NOT GIVE. The extract of ISO 17892-4:2016 made available by the publisher reaches 5.1. WE DO NOT HAVE the course of sieving (5.2), of sedimentation (5.3, 5.4), the calculations (clause 6 — including the hydrometer reading corrections, the effective depth, the correction for material above 2 mm) or the required sample masses. We do not give these values.

Method principle

The soil portion is sieved through a set of sieves and the residues on each sieve are weighed — this gives the distribution of particles larger than 0.063 mm. The finer fraction is tested by sedimentation: a dispersed suspension of soil in water is left in a cylinder, and the density of the suspension is measured with a hydrometer, or samples are taken with a pipette from a specified depth at a specified time. The equivalent diameter of the particles that have settled in that time is calculated from Stokes' law. Both results are combined into one grading curve.

Applications

• Classification of soils in geotechnical investigation (ISO 14688) and in ground investigation documentation
• Design of foundations, embankments, slopes and retaining structures — tests according to EN 1997-2
• Assessment of the permeability properties of soils
• Bottom and marine sediments — in the accreditation scopes

Key parameters

Standard

Standard number

PN-EN ISO 17892-4:2017-01 (wersja angielska; wprowadza EN ISO 17892-4:2016 [IDT], ISO 17892-4:2016 [IDT])

Title (PL)

Rozpoznanie i badania geotechniczne — Badania laboratoryjne gruntów — Część 4: Badanie uziarnienia gruntów

Title (EN)

Geotechnical investigation and testing — Laboratory testing of soil — Part 4: Determination of particle size distribution

Step-by-step procedure

1. Choice of method

   On the basis of the composition of the sample (rules of 5.1): sieving, hydrometer or pipette sedimentation, or a combination.

2. Sample preparation

   If necessary, removal of organic matter (H2O2) and carbonates (HCl) according to Annex B; WE DO NOT GIVE the sample masses.

3. Sieving

   On a set of sieves covering the recommended sizes; the residues are weighed. WE DO NOT GIVE the procedure of 5.2.

4. Sedimentation

   Suspension with a dispersing agent in a cylinder, temperature constant within 3 °C; hydrometer readings or pipette samplings at specified times. WE DO NOT GIVE the procedure of 5.3–5.4.

5. Calculations and curve

   The fraction proportions from sieving and the equivalent diameters from sedimentation are combined into a grading curve (clause 6 — WE DO NOT GIVE the formulas).

6. Report

   State the method used (sieving, hydrometer, pipette, combined) — in the accreditation scope it corresponds to clauses 5.2–5.5.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Hydrogen peroxide 20 % — gloves and goggles, the reaction with organic matter can be violent
• Hydrochloric acid — gloves and goggles
• Sieve shaker — noise and moving parts

Frequently asked questions