Controlled Environments/Cleanrooms
« Controlled Environments/Cleanrooms GT-321 Handheld Particle Counter

GT-321 Handheld Particle Counter

Met One Instruments’ handheld GT-321 is a portable particle counter that counts particles down to 0.3 microns—giving you portability and reliability at very competitive prices. Don’t let the size fool you—the GT-321 is completely self- contained with its own internal battery and sample pump. The 321 is programmable, allowing you to choose your particle size of interest from five sizes: 0.3, 0.5, 1.0, 2.0, or 5.0 microns. Unlike other counters that can take up to a minute to deliver results, the GT-321 starts delivering volumetric concentration results in about 6 seconds! This facilitates quick multi-site sampling, tracing particle sources and site particle trending.


The GT-321 is simple operation with only two front-panel buttons to control the size channels and sample cycle. The side-mounted power switch allows for convenient thumb operation. The self-contained battery pack powers the unit for 8 hours of typical intermittent operation, and up to 5 hours of continuous use. The included AC adapter/charger operates the 321, even when the battery pack is discharged, and recharges the depleted battery overnight (16 hours) when the unit is turned off. Units are typically available for same-day or next-day shipping!


  • Select Between Five Particle Sizes – 0.3, 0.5, 1.0, 2.0, or 5.0 Microns
  • Simple Operation
  • Fast Sampling
  • Battery or AC Powered
  • Keypad Selectable Sizes
  • High resistance values to minimize signal line resistance
  • 1-Year Warranty


  • Controlled Environments
  • Indoor Air Quality
  • Process Control
  • HVAC Applications
  • Filter Testing
  • Laboratory Environments
  • Manufacturing Environments
  • Emission Sourcing


User Manual
Serial Cable
AC to DC Converter with AC Power Cord
Iso-kinetic Sample Probe
Carrying Case
Zero Particulate Filter
NIST Certificate of Calibration


Flow Meter (P/N 9801)

Specifications are subject to change at any time

1800 Washington Bivd

Grants Pass, OR 97526

Phone: 541-471-7111

Fax: 541-471-7116



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