MET ONE GT-324 Handheld Laser Particle Counter

Overview

The MET ONE GT-324 Handheld Laser Particle Counter is a precision-engineered instrument designed for real-time airborne particulate monitoring in cleanroom validation, pharmaceutical manufacturing environments, HVAC system verification, and controlled laboratory settings. It operates on the principle of single-particle light scattering—using a 780 nm laser diode to illuminate aerosolized particles drawn through a calibrated 2.83 L/min sampling flow path. Scattered light pulses are detected by a high-sensitivity photodetector and classified into user-selectable size bins based on pulse amplitude thresholds. The device complies with ISO 21501-4:2018, the international standard governing calibration, performance verification, and reporting requirements for light-scattering airborne particle counters. Its compact form factor (15.9 × 9.38 × 5.1 cm), integrated temperature and relative humidity sensor, and extended battery life (11 hours continuous operation) enable robust field deployment without compromising metrological integrity.

Key Features

• Four independently configurable particle size channels selected from seven standardized thresholds: 0.3, 0.5, 0.7, 1.0, 2.5, 5.0, and 10.0 µm—supporting compliance with ISO 14644-1, EU GMP Annex 1, and USP particulate matter testing protocols.
• Integrated environmental sensing: Onboard temperature and relative humidity sensors provide concurrent environmental context for each sample record, critical for trending and root-cause analysis in regulated environments.
• High-fidelity data acquisition: Each sample captures time-stamped concentration values per channel, along with ambient conditions, operator ID, location tag, and sampling duration (adjustable from 3 to 60 seconds).
• Secure user management: Password-protected configuration interface aligned with FDA 21 CFR Part 11 requirements—ensuring audit trails, electronic signature capability, and prevention of unauthorized parameter modification.
• Robust mechanical architecture: Sealed optical chamber, shock-absorbing elastomeric housing, and IP54-rated ingress protection for reliable operation in dynamic industrial or clinical settings.

Sample Compatibility & Compliance

The GT-324 is validated for use with ambient air, compressed gases (filtered to ≤0.01 µm), and HEPA-filtered room air. It is not intended for corrosive, explosive, or highly viscous aerosols. All calibration certificates trace to NIST-traceable reference standards per ISO 21501-4 procedures. Device firmware and data handling workflows support GLP/GMP documentation requirements—including full metadata retention, immutable timestamping, and export-ready CSV/ASCII formats. Validation documentation packages (IQ/OQ/PQ templates) are available upon request for integration into facility qualification programs.

Software & Data Management

Data retrieval and analysis are supported via two complementary software platforms: Comet Software (for basic download, filtering, and report generation) and ParticleView™ (a full-featured desktop application supporting statistical process control charts, alarm threshold configuration, batch comparison, and PDF/Excel export). All exported datasets include full audit trail logs—capturing user actions, timestamps, and system events per 21 CFR Part 11 Subpart B. USB communication enables direct connection to Windows-based systems without proprietary drivers; firmware updates are performed via signed binary packages to ensure cryptographic integrity.

Applications

• Cleanroom classification and routine monitoring per ISO 14644-1 Class 5–8 environments
• Filter integrity testing (e.g., pre- and post-HVAC filter challenge studies)
• Pharmaceutical aseptic processing line qualification and environmental monitoring (EM) programs
• Medical device packaging area surveillance and sterile barrier validation
• Research-grade aerosol characterization in university clean labs and microelectronics fabrication facilities
• Compressed air quality assessment per ISO 8573-1:2010 Class 2–4 particulate specifications

FAQ

What calibration standards does the GT-324 reference?
The instrument is factory-calibrated using NIST-traceable PSL (polystyrene latex) spheres per ISO 21501-4 Annex A, with documented uncertainty budgets available in the Certificate of Conformance.
Can the GT-324 be used for ISO 14644-3 testing?
Yes—it meets the minimum sensitivity (≥0.3 µm), flow rate stability (±5%), and counting efficiency requirements specified for airborne particle counters in ISO 14644-3:2019 Annex B.
Is remote data logging possible?
No—the GT-324 lacks built-in Wi-Fi or Ethernet; however, scheduled manual downloads via USB maintain full data integrity and chain-of-custody compliance.
Does the device support multi-user login with role-based permissions?
It supports two-tier access: Operator mode (sample start/stop, basic settings) and Administrator mode (calibration, alarm thresholds, user management)—both enforced via alphanumeric password authentication.
How is battery health monitored during field use?
The LCD displays real-time battery voltage and estimated remaining runtime; low-battery warnings activate at ≤12% capacity, and the system auto-saves all unsaved data before shutdown.