Ahead
in single
particle
analysis

Size. Count. Classify.

Resolve heterogeneous particle populations beyond the limits of traditional particle sizing.

EOS Instruments develops the Classizer™ family of particle analyzers, powered by patented SPES technologies — Single Particle Extinction and Scattering. Classizer™ optically classifies individual particles providing particle size, absolute concentration and effective refractive index
in complex heterogeneous liquid and airborne samples. 

Discover SPES
Find your application

A picture of the Classizer ONE instrument equipped with the Sample manager in the lab


Main applications

Scientific and industrial fields where SPES is ahead in particle analysis.

Discover all

Polymeric particlesPrecise refractive index, size distribution, aggregation and oversize analysis of polymeric particles in mixtures.Discover more →Particle engineeringPlasmonic and metallic NPs, structured particles, nanocapsules and exotic systems: SPES will be your workhorse.Discover more →Environmental studiesNano and microplastics, black carbon particles, minerals and aerosols: SPES innovates in environmental studies.Discover more →Milling and homogenisationUnderstand and optimise milling performance, stability and homogenisation of single components in blends.Discover more →
The instrument

Classizer™ ONE

EOS Instruments produces the Classizer™ ONE, the new standard in particle analysis. A novel, complete analytical platform that redefines optical particle sizing.

Up to 3 independent SPES optical parameters per particleEffective Refractive Index measurementCalibration-free particle sizing and absolute concentrationIsolate single components in complex, heterogeneous samplesDiscover the ClassizerGet a free test measurement

100/200* nm – 20 µm
Size range
≈ 5 min
per sample
Any solvent
Broad compatibility
Tailored
Highly customisable
*down to 100 nm for absorbing particles; 200 nm for typical dielectric particles
SPES technologyThe patented optical principle behind every Classizer™ measurement.Software & add-onsIntuitive acquisition and analysis, with Principal Component Analysis, Continuous Flow Analysis and bubble identification add-ons.AccessoriesEOS Instruments provides sample manager, autosamplers and autodilutors for faster, reliable runs.Lab-as-a-ServiceSend us your samples!
Tailored contract analysis and method development.
The technology

SPES — Single Particle Extinction and Scattering

SPES is the patented technology developed by EOS Instruments that lies at the core of our particle analyzers. It measures the complex forward-scattered electric field of each particle directly — both real and imaginary components, not just the intensity — obtaining a unique, truly multiparametric optical fingerprint.
01Retrieves the complex, forward-scattered electric field for each particle
02Each particle is measured individually — no ensemble averaging
03Self-referenced and absolute — no calibration needed
04Understand particle’s complexity and fit custom theoretical models to data

Explore SPES

scheme of SPES technology
SPES scheme animated
Testimonials

What our partners say

Read all the testimonials

“

One of our scientific interests is how the concentration, size distribution and refractive index of particles may have changed over time scales from seasons to hundreds of thousands of years. Our Classizer™ ONE allows for the analysis of particles smaller than 1 µm in a continuous ice core melt water stream, which has previously not been possible with other particle sizing instruments…
Prof. Hubertus Fischer
Professor, Deputy Head of Division Climate and Environmental Physics @ University of Bern (CH)
“

The unique advantages of the Classizer™ ONE are providing us with valuable insight into complex nanoparticle systems where traditional techniques like electron microscopy or dynamic light scattering provide limited information.
Prof. Robin Klupp Taylor
Professor, Institute of Particle Technology,
Friedrich-Alexander-University Erlangen-Nürnberg (DE)
“

The unique combination of counting and sizing particles, hence obtaining a particle size number distribution from 0.2 to 20 µm, and the ability to classify particles on the basis of their optical properties, gives us an unprecedented insight in the nature of our dispersions.
Bart Wuytens
Manager Physico-Chemistry @ Agfa-Gevaert NV (BE)
Get started with SPES

Send us your samples!

Curious about SPES? No commitment — tell us what you’re working on and we’ll assess whether SPES is a good fit, and measure up to five samples at no cost.
01Describe your samples in the form
02We confirm the fit and arrange the shipment with you
03We measure up to five samples free of charge and review the results together on a call
Before you send us your samples
• Up to 5 samples per free assessment.
• We usually perform these tests in deionised water. Let us know if your sample requires a different dispersion medium or a specific preparation protocol, such as a specific pH.
• Shipment of powders and other non-liquid samples must be agreed in advance. Our lab does not handle materials requiring a fume hood.
• Limited lab capacity, offer subject to availability.
Request a free measurement