The Application Of Laser Particle Size Analyzers

Introduction

Laser particle size analyzers, particularly those using laser diffraction, are widely used across various industries for measuring particle size distribution.

In research, these analyzers help in the development of new materials by providing detailed particle size information.

In quality control, they ensure that manufactured goods meet specific particle size requirements, which is crucial for product consistency and performance.

Industries such as pharmaceuticals, chemicals, food and beverage, and environmental monitoring heavily rely on laser particle size analyzers for their precision and efficiency.

The technology is also used in the production of ceramics, where accurate particle size measurement is vital for the quality of the final product.

Principles of Laser Diffraction

Laser diffraction measures particle size distributions by analyzing the angular variation in light intensity scattered by particles.

Large particles scatter light at small angles, while small particles scatter light at larger angles.

The Mie theory of light scattering is used to calculate particle size distribution, assuming a volume equivalent sphere model.

The Fraunhofer approximation can be used for large particles, providing accurate results without needing optical property data.

Laser diffraction is covered by ISO13320 (2020), making it a well-established and standardized technique.

Figure 1: A simplified layout of the LA-960 Laser Diffraction Particle Size Analyzer optical bench

Pharmaceutical Applications

Laser diffraction analyzers are used to characterize drug particles, excipients, and formulations.

They ensure uniformity and stability of pharmaceutical products by providing precise control over particle size distribution.

Instruments like the Spraytec are used for analyzing spray particle size in inhalation drug delivery systems.

This technology helps optimize aerosol performance and drug delivery efficiency.

Real-time monitoring capabilities support quality control and process optimization in pharmaceutical manufacturing.

Figure 2: Basic Optical System of a Laser Diffraction Particle Size Analyzer

Chemical Industry Applications

Laser diffraction is used to analyze particulate materials like polymers, pigments, and catalysts.

It provides insights into particle size distribution and surface area, aiding in quality control and process optimization.

Real-time particle size monitoring in chemical manufacturing processes ensures product consistency and minimizes waste.

Instruments like the Insitec range offer continuous particle size analysis, supporting efficient manufacturing operations.

The technology helps in the development of new chemical products by providing detailed particle size data.

Environmental Monitoring

Laser diffraction analyzers are used for analyzing particulate pollutants, aerosols, and sediments.

They provide valuable data for assessing air and water quality, studying particle dynamics, and understanding pollutant impacts.

Real-time monitoring capabilities enable timely intervention and management of environmental contaminants.

Instruments like the Insitec range offer continuous particle size analysis for environmental applications.

The technology supports research in environmental science by providing detailed particle size distribution data.

Enhanced Laser Diffraction

Enhanced laser diffraction uses polarisation intensity differential scattering (PIDS) to measure particles down to 10 nm.

It provides real measured size distributions rather than estimates, improving accuracy for sub-micron particles.

The technology is used in soil studies, pigment sizing, and quality control of chemical compounds.

Enhanced laser diffraction offers superior resolution and unmatched dynamic range compared to conventional techniques.

Instruments like the LS 13 320 XR are capable of performing enhanced laser diffraction analysis for various applications.

Figure 3: Laser Diffraction