Particle Size Distribution Test

Particle Size Distribution Test
(Sieve Analysis & Hydrometer — IS 2720 Part 4)

Complete particle size distribution of soil by sieve analysis (coarse fraction) and hydrometer method (fine fraction) per IS 2720 Part 4 — for soil classification, permeability estimation and pavement design.

Overview

What is the Particle Size Distribution Test?

Particle Size Distribution (PSD) — also called grain size analysis — determines the range and distribution of particle sizes in a soil sample. Coarse fractions (>75μm) are separated by mechanical sieve analysis through IS sieve series. Fine fractions (<75μm — silt and clay) are analysed by the hydrometer method based on Stokes' law — the rate of sedimentation of particles in a water suspension is related to particle diameter.

Conducted as per IS 2720 Part 4, PSD provides the gravel, sand, silt and clay fractions — directly used in IS 1498 soil classification (GW, GP, GM, GC, SW, SP, SM, SC, CL, CH, ML, MH), permeability estimation, filter design, stabilisation design and pavement subgrade assessment. Global Lab conducts combined sieve + hydrometer analysis covering the full particle size range from 80mm down to 0.001mm.

Combined Sieve + Hydrometer

Full PSD from 80mm down to 0.001mm — coarse by sieve, fine by hydrometer.

IS 1498 Soil Classification

Gravel/sand/silt/clay fractions used for USCS/IS 1498 soil classification.

D10, D30, D60 Determination

Effective size (D10), D30 and D60 read for Cu and Cc uniformity coefficients.

Hydrometer Sedimentation

IS 2720 Part 4 hydrometer method for clay and silt fraction — readings at 8 time intervals.

NABL Certified Reports

All test and calibration results are backed by traceable measurements and standardized procedures.

Permeability Estimation

D10 used in Hazen's formula for permeability estimation of granular soils.

Test in Action

Particle Size Distribution Test — Site Images

IS Sieve Series — Mechanical Sieve Shaker for Coarse Fraction

Hydrometer in Soil Suspension — Sedimentation Analysis

Combined PSD Curve — Sieve + Hydrometer on Semi-Log Graph

Test Procedure

How the Particle Size Distribution Test is Conducted

1

Sample Preparation

Soil air-dried, lumps broken gently. Sieved through 4.75mm sieve — coarse and fine portions separated.
2

Sieve Analysis (Coarse Fraction)

Coarse fraction sieved through IS sieve series (80mm to 4.75mm to 75μm) in mechanical sieve shaker. Mass on each sieve recorded.
3

Hydrometer Analysis (Fine Fraction)

50g minus 75μm fraction dispersed with sodium hexametaphosphate. Hydrometer readings at 0.5, 1, 2, 4, 8, 15, 30, 60, 120 and 1440 minutes.
4

Combined PSD Curve

Percentage passing calculated for each sieve and hydrometer point. Combined PSD curve plotted on semi-log graph.
5

IS 1498 Classification & Report

D10, D30, D60 read. Cu and Cc calculated. Soil classified per IS 1498. NABL report within 5 days.

Standards & Specifications

Applicable Test Standards

Standard	Title	Scope	Type
IS 2720 Part 4	Methods of Test for Soils — Grain Size Analysis	PSD Test	Indian Standard
IS 1498	Classification and Identification of Soils for General Engineering Purposes	Soil Classification	Indian Standard
IS 2720 Part 5	Methods of Test for Soils — Determination of Liquid and Plastic Limit	Atterberg Reference	Indian Standard
ASTM D422	Standard Test Method for Particle-Size Analysis of Soils	PSD Standard	ASTM

Applications

Where is the Particle Size Distribution Test Used?

Soil classification for geotechnical investigation reports on all projects

Filter design for drainage systems, retaining walls and earth dams

Highway subgrade soil classification per MORTH and IRC specifications

Pavement sub-base and base course aggregate grading check

Soil stabilisation design — identifying silt/clay content for lime/cement dosage

Contaminated site investigation — particle size analysis for permeability assessment

Why Choose Global Lab

Our Advantages

NABL Accredited ReportsLegally valid IS 2720 Part 4 certificates for all geotechnical design requirements.

Full Range — 80mm to 0.001mmCombined sieve + hydrometer covers complete particle size range in one test.

IS 1498 Classification IncludedComplete USCS-equivalent IS 1498 soil classification in every report.

Fast 5-Day ReportComplete PSD including hydrometer readings and NABL report within 5 days.

Pan-India CoverageGeotechnical lab at all 7 NABL-accredited locations.

Combined Soil PackagePSD + Atterberg + Compaction + CBR as a complete geotechnical characterisation.

Particle Size Distribution Test(Sieve Analysis & Hydrometer — IS 2720 Part 4)