Automatic Laser Particle Size Analyzer

Overview

The Automatic Laser Particle Size Analyzer is a dual-method (wet and dry) instrument built on laser diffraction and Mie theory calculations. It measures particle size distributions from 0.01 µm to 1250 µm using forward, side, and back scattering detectors arranged in a converging Fourier transform optical configuration. One-button software switching between wet and dry modes eliminates the need for separate instruments or manual reconfiguration, making it suitable for research laboratories, quality control departments, and production environments across pharmaceutical, materials science, chemical, and environmental applications.

Key Features

• Wide measurement range: 0.01–1250 µm (wet), 0.1–1250 µm (dry) in a single platform
• High channel count: 112 detector channels (wet) / 102 channels (dry) for high-resolution distributions
• Sub-1% accuracy: <1% error on D50 for both wet and dry methods against national standard reference materials
• Fast measurement: <1 minute per test (excluding sample dispersion time)
• Integrated ultrasonic dispersion: 40 kHz, 80 W with adjustable duration and anti-dry protection
• Variable-speed circulation: 100–3950 rpm with 0–10 L/min adjustable flow rate
• High-pressure air dry dispersion with oil-free mute compressor and freeze-dryer moisture filtration
• Real-time shading (obscuration) detection for consistent sample concentration
• Residue-free, bubble-free sample cell design (190–600 mL capacity)
• Dust-proof, shockproof construction with self-protection against misoperation
• GMP-ready: 21 CFR Part 11 compliance capability with full audit trail

Dual Wet/Dry Analysis

The instrument integrates both wet and dry dispersion methods in a single unit with software-controlled one-button switching between modes.

Wet Method

The sample is added to the sample barrel, where integrated ultrasonic treatment (40 kHz, 80 W) and high-speed circulation (up to 3950 rpm) disperse the particles through the measurement window. The boiling-type sample pool design with 190–600 mL capacity ensures thorough dispersion and residue-free operation. Anti-dry ultrasound protection prevents transducer damage if the cell runs dry.

Dry Method

The sample is introduced via a mechanically regulated vibration feeder with stepless speed control. A negative-pressure dispersion pump drives particles through the measurement zone using high-pressure air dispersion. The integrated oil-free air compressor with dust filtration and freeze-dryer moisture removal ensures clean, consistent dispersion conditions for moisture-sensitive or agglomeration-prone powders.

Measurement Principle

The analyzer uses laser diffraction to determine particle size distributions based on the angular intensity of scattered light as a laser beam passes through a dispersed sample. Larger particles scatter light at smaller angles relative to the beam, while smaller particles produce scattering at larger angles. The instrument employs a converging Fourier transform optical design that maximizes the detectable size range within a short focal length. Forward, side, and back scattering detectors with high-density detection elements capture the full scattering pattern, which is then processed using Mie scattering theory to calculate the volumetric particle size distribution.

Software & Data Analysis

• Automated Standard Operating Procedure (SOP) creation and execution
• Comprehensive report outputs: D10, D50, D90, D[4,3] (volume mean), D[3,2] (surface area mean), Span, Obscuration, Uniformity, specific surface area (S/V), and surface area per gram (S/g)
• Built-in refractive index material database for accurate Mie theory calculations
• Data averaging, comparison, and overlay analysis across multiple measurements
• Export to standard formats for integration with LIMS and reporting workflows
• 21 CFR Part 11 audit trail support: user authentication, electronic signatures, and change logging for GMP-regulated environments

Compliance & Regulatory

The instrument and its software support GMP-compliant workflows with 21 CFR Part 11 capabilities including user-level access control, electronic signatures, and a complete audit trail for all measurements and system changes. The system is suitable for regulated pharmaceutical, food, and environmental testing environments where data integrity and traceability are required.