An Engineer’s Guide to Particle Size Analyzers

May 23, 2025

Particle size and distribution are critical to the performance, processing behavior, and quality of particulate materials across industries—from pharmaceuticals and food to mining, construction, and advanced materials. Engineers involved in product development, quality control, and process optimization need a solid grasp of particle sizing techniques, their principles, and their appropriate applications. This guide explores the leading technologies available today and how ATS-Scientific's particle analysis solutions meet the complex demands of modern industry.

Why Particle Size Matters

Particle size distribution affects a material’s surface area, flowability, reactivity, and packing density. For instance, smaller particles increase surface area and dissolution rates (key for pharmaceutical tablets), while larger, more uniform particles improve flow in manufacturing and reduce dust.

Precise particle size measurement enables engineers to:

Predict product behavior (e.g., solubility, absorption, sedimentation)
Optimize manufacturing (e.g., mixing, milling, spray drying)
Ensure consistency and compliance in final products

Primary Techniques for Particle Size Analysis

Laser Diffraction (LD): This widely used technique measures the angle and intensity of light scattered by a dispersed particulate sample. Laser diffraction is based on Mie theory and provides rapid, reproducible volume-based particle size distributions over a wide range (from submicron to millimeter scale). ATS-Scientific offers advanced laser diffraction analyzers, including integrated systems like the Microtrac SYNC, which combines LD with image analysis for dual data outputs.
Dynamic Image Analysis (DIA): DIA captures high-speed images of particles in flow and uses software to analyze size and shape characteristics, such as circularity, elongation, and aspect ratio. Unlike LD, which infers spherical equivalent diameter, image analysis delivers true shape and size data. The SYNC analyzer from ATS allows simultaneous LD and DIA analysis in a single workflow, giving engineers a more complete picture of particle morphology and distribution.
Dynamic Light Scattering (DLS): DLS determines the hydrodynamic size of small particles (typically below 1 micron) in suspension by measuring fluctuations in light scattering due to Brownian motion. It is ideal for nanoparticle analysis but less suitable for broad or polydisperse samples.
Sieve Analysis and Sedimentation: Traditional techniques like sieve stacks or sedimentation (Stokes' Law) are still used for coarse or specific applications but are slower, less automated, and limited in resolution compared to optical techniques.

Choosing the Right Method to Measure Particles

Each particle size analysis technique has strengths and trade-offs:

Laser Diffraction is ideal for fast, high-throughput sizing of powders and slurries with wide distributions.
Dynamic Image Analysis is best when particle shape and structure matter (e.g., needles, flakes, granules).
DLS is necessary for nanoparticle suspensions in colloid chemistry or biological formulations.

Key factors when selecting a particle sizing method include:

Sample type (wet or dry)
Size range and distribution
Required throughput and automation
Sensitivity to particle shape and agglomerates

ATS-Scientific supports engineers in method selection, offering modular systems with both dry and wet dispersion capabilities, high-resolution optics, and intuitive software.

ATS-Scientific Solutions for Particle Sizing

ATS offers a full range of particle size analyzers, including:

Microtrac SYNC: Combines laser diffraction and image analysis for comprehensive particle characterization in a single instrument.
S3500 Series: A modular laser diffraction system for high-volume QC and research applications.
Nanotrac Wave II: DLS-based analyzer for nanomaterials and submicron particles.
Aerotrac and Beltac series: Designed for aerosol and environmental particle analysis.

These systems are equipped with automation options, wet and dry dispersion modules, and software for real-time visualization, trend analysis, and regulatory documentation. ATS also provides application support, calibration standards, and service plans to ensure long-term performance.

Best Practices for Reliable Data

Regardless of the technique, good practices in sample preparation, dispersion, and instrument calibration are essential:

Dispersion: Agglomerated particles must be properly dispersed, using ultrasonic treatment or surfactants if necessary.
Refractive Index: Correct input of sample and dispersant refractive indices is crucial for LD and DLS accuracy.
Validation: Use certified reference materials (CRMs) and perform regular checks with standard samples.
Environmental Control: For nanomaterials, temperature and vibration stability can affect DLS results.

ATS helps labs establish SOPs and offers training to ensure reproducible, defensible data.

Interested in Upgrading to a Particle Size Analyzer?

Understanding particle size analysis is vital for engineers tasked with material development, process optimization, or quality control. With a range of techniques suited to different particle types and applications, choosing the right tool requires both technical knowledge and hands-on support.

ATS-Scientific delivers advanced particle analysis systems and expert guidance to help engineers get the accurate, actionable data they need. Whether measuring cement powders, pharmaceutical granules, or food emulsions, ATS's solutions ensure precision, compliance, and confidence in every analysis.