The reliability you demand at a price you won’t believe! 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...