GT-321 Single Channel Particle Counter
Small Size—Big Performance
The handheld GT-321 is a portable particle counter that counts particles down to 0.3 microns—giving you portability and reliability at the lowest price in the industry.
- Completely Self-Contained—Selectable Particle Sizes
- Don’t let the size fool you—the GT-321 is completely self-contained with its own internal battery and sample pump, and 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.
- Fast Sampling
- 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.
- Simple Operation
- Only two front-panel buttons control the size channels and sample cycle. The side-mounted power switch allows for convenient thumb operation.
- Battery or AC Powered
- The self-contained battery pack powers the unit for 8 hours of typical intermittent operation, and for up to 5 hours of continuous use. The included AC adapter operates the counter, even when the battery pack is discharged, and recharges the depleted battery overnight (16 hours) when turned off.
- Off-the-Shelf Delivery
- Units are available for same-day or next-day shipping!
For more information please visit Met One Instruments GT-321 Single Channel Particle Counter

















