Particle Size Analyzer (PSA)
**Physical Characterization / Material Science / Powder Technology**
Particle Size Analysis determines the size range and distribution of particles in a powder or liquid sample . Using techniques like laser diffraction, the analyzer measures how particles scatter light to calculate their size distribution . This information is critical because particle size directly influences material properties such as solubility, bioavailability, texture, stability, and reactivity across industries from pharmaceuticals to construction . The Particle Size Analyzer determines particle size distribution—the relative amount of particles present across different size fractions . The most widely used technology is **laser diffraction (LD)**, based on the principle that smaller particles scatter light at larger angles . **How Laser Diffraction Works:** 1. **Sample Dispersion:** The sample (powder or liquid suspension) is dispersed in a suitable medium (water, air, or organic solvent) . 2. **Laser Illumination:** A laser beam passes through the dispersed particles . 3. **Scattering Pattern Detection:** The scattered light is focused onto an array of detectors that measure intensity at various angles . 4. **Mathematical Modeling:** Using Mie or Fraunhofer scattering theory, the instrument calculates the particle size distribution that would produce the observed scattering pattern . **Alternative Techniques:** - **Dynamic Light Scattering (DLS):** Measures Brownian motion of submicron particles in suspension to determine hydrodynamic size (Stokes-Einstein equation) . Industry standard for nanoparticles and proteins. - **Sieve Analysis:** Traditional method separating particles by mesh size . - **Image Analysis:** Digital imaging for size and shape information . Results are typically presented as a **frequency distribution histogram** (percentage of particles in each size fraction) and a **cumulative undersize distribution curve** (percentage of particles smaller than a given size) .
Test specification
- Methodology
1. **Sample Preparation:** Sample is weighed (10 mg–5 g) and dispersed in appropriate liquid medium or loaded as dry powder . 2. **Dispersion System Setup:** For wet measurements, sample is circulated through the flow cell with pump speed and ultrasonic dispersion parameters set . 3. **Background Measurement:** Baseline reading without sample accounts for instrument and dispersant contributions. 4. **Sample Measurement:** Laser diffraction or other method records scattering pattern . 5. **Data Analysis:** Software applies mathematical models (Mie or Fraunhofer scattering theory) to calculate particle size distribution . 6. **Result Reporting:** Distribution curves (frequency and cumulative) with statistical parameters (D10, D50, D90) are generated.
- Standards followed
- **ASTM E2651** – Standard Guide for Powder Particle Size Analysis . - **ASTM C690** – Standard Test Method for Particle Size Distribution of Alumina or Quartz by Electric Sensing Zone Technique . - **ISO standards** for various particle sizing techniques (ISO 13320 for laser diffraction). - **USP <429>** for pharmaceutical particle size analysis.
- Equipment used
- - **Laser Diffraction PSA:** e.g., Anton Paar PSA series (1190, 1090), Horiba LA-960S . - **Measurement range:** 0.01 µm – 5000 µm (depending on model) . - **Accessories:** Wet and dry dispersion units, flow cells, autosamplers. - **Software:** Dedicated particle size analysis software (Kalliope™, Method Expert) . - **Alternative systems:** DLS instruments for submicron measurement
- sieves for traditional analysis .
- Parameters measured
- **Particle Size Distribution (PSD):** Frequency distribution (histogram) and cumulative undersize distribution . - **Statistical parameters:** - D10: 10% of particles are smaller than this size - D50: Median particle size (50% below, 50% above) - D90: 90% of particles are smaller than this size - **Mean particle size:** Various averaging methods. - **Distribution width:** Span = (D90 – D10) / D50. - **Mode:** Most frequent particle size.
- Measurement range
- **Typical laser diffraction range:** 0.01 µm to 5000 µm . - **Wet dispersion:** 0.01 µm – 1250 µm (depending on model) . - **Dry dispersion:** 0.1 µm – 2500 µm . - **DLS (submicron):** 1 nm – 10 µm (typical). - **Sieve analysis:** > 20 µm.
- Accuracy / detection limit
- - **Repeatability:** High reproducibility—one of the key advantages of laser diffraction PSA . - **Sensitivity:** Detects particles down to nanoscale (0.01 µm / 10 nm) . - **Accuracy:** Depends on proper method selection, sample dispersion, and refractive index knowledge
- generally reliable within ± 3–5% for well-characterized samples. - **Rapid measurement:** < 1 minute per test (excluding dispersion time) .
Suitability
- Applications
- - **Pharmaceuticals:** Drug development—particle size affects solubility, bioavailability, and shelf life of APIsquality control of mRNA vaccines formulated in lipid nanoparticles . - **Cosmetics:** Product formulation—particle size influences texture, gloss, and performance . - **Food & Beverages:** Quality control for milled products (coffee, flour, cocoa powder)chocolate qualitypredicting stability and shelf-life of emulsions . - **Chemicals & Materials:** Production of composite materials where size affects physical and chemical properties . - **Mining & Minerals:** Classification and processingeffectiveness of SAG mills . - **Construction & Cement:** Particle size directly affects final material strength . - **Agriculture:** Soil texture analysis affecting water/nutrient retentionclassification of sand, silt, and clay . - **Paints & Coatings:** Influences tint strength, hiding power, gloss, viscosity, stability, and weather resistance . - **Biology & Nanomedicine:** Protein aggregation studiesnanoparticle drug delivery characterization .
- Industries served
- - Pharmaceutical and biotechnology - Food and beverage processing - Cosmetics and personal care - Chemical manufacturing - Mining and minerals processing - Construction and building materials - Agriculture and environmental science - Paints, coatings, and pigments - Polymer and plastics industry - Research and academic institutions - Nanotechnology and advanced materials
- Advantages
- **Broad dynamic range:** Measures from nanometers to millimeters . - **Rapid measurement:** < 1 minute per sample . - **Highly reproducible** and repeatable . - **Versatile:** Handles powders, suspensions, emulsions, pastes, gels, and creams . - **Minimal sample preparation** for many sample types. - **Wet and dry measurement modes** available . - **Automated testing** with guided method selection . - **Non-destructive** analysis. - **Critical quality control tool** across industries .
- Limitations
- - **Assumes spherical particles:** Results are "equivalent spherical diameter"
- irregular shapes may be misrepresented. - **Refractive index input required** for Mie theory calculations . - **Dilution required:** Mostly restricted to dilute suspensions
- dense slurries require complex corrections . - **Different techniques give different results:** Sieve analysis, laser diffraction, and image analysis will not produce identical results . - **Aggregation/agglomeration** can skew results
- proper dispersion is critical. - **Large instrument footprint:** ~700 × 300 × 450 mm and heavy (~30 kg) . - **High capital cost:** Typically 50,000–200,000 EUR . - **Requires trained personnel** and regular maintenance .
Submitting a sample
- Sample requirement
- **Sample mass:** Typically **10 mg to 5 g** per measurement . - **Dispersion volume:** Up to **280 mL** of dispersant (water or organic solvent) . - **Solvent compatibility:** Most organic solvents—wetted materials include stainless steel, perfluorolastomer, Teflon, titanium, and glass . - **Dispersion:** Sample must be well-dispersed (ultrasonic dispersion may be used) to avoid particle agglomeration . - **Refractive index:** Prior knowledge of particle and dispersant refractive indices may be required for Mie theory calculations .
- Turnaround time
- **Routine analysis:** 1–3 working days (depending on sample load). - **Express analysis:** 24 hours (available upon request). - **Instrument measurement:** < 1 minute per sample (sample preparation and dispersion may add time).
- Deliverables
- Official test certificate/report with detailed particle size results. - Particle size distribution curves: - Frequency distribution histogram - Cumulative undersize distribution curve - Statistical data: D10, D50, D90 values. - Mean particle size and distribution span. - Raw data files (if requested). - Comparison with specifications or quality standards (if specified).
Request this test
Send us your sample details and we'll confirm scope and timing.