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GT-521S Handheld Particle Counter

Product SKU: GT-521S

Quick Overview

Battery-operated, portable the GT-521S is a fully featured particle counter. With all the power and function of a bench unit, yet conveniently in a handheld size, the GT-521S supports differential and cumulative counts, total counts, count alarms, and standard concentrations. Additionally, it can datalog particle counts either continuously or send them to a network.


With an aluminum enclosure your instrument is protected from scrapes and bumps, which normally would damage plastic devices. A sturdy carrying case comes with your counter.


Easily select your particle sizes on the GT-521S with two programmable count channels, each with 0.3 to 10 microns. These channels show cumulative and differential particles counts in real time with selectable count units.

Among the excellent features that the GT-521S possesses is the powerful yet simple menu-driven command set. Just the touch of a button will set sample time, particle sizes, alarm settings, and basic set-up parameters like date and time communications settings. Via RS-232 or RS-485 communication ports, remote operation is possible and allows for absolute control, inclusive of front-panel operations. In addition, you can view sample history on the local display or download to a computer with Comet software. Plus, the GT-521S can store up to 8,000 sample events and up to 4,000 records for printer output, Excel®-formatted output, or networked data-logging via the included single-included software (GT-Comm).

Additionally, the GT-521S may also feature a temperature and/or relative humidity plug-and-play option – a helpful option to immediately add ambient temperature and relative humidity capabilities to the displayed and logged data.

The GT-521S is a battery-powered device with 24 hours of typical, intermittent operation or 10 hours of constant operation from a single charge. Only approximately 2.5 hours of recharging time.


  • 2 channels of monitoring user selectable

  • Simple & powerful menu driven functionality

  • Adjustable sample time

  • Differential or cumulative

  • Battery or AC Powered


  • Controlled Environments

  • Indoor Air Quality

  • Process Control

  • HVAC Applications

  • Filter Testing

  • Compliance Testing

  • Emission Sourcing

  • Remote Sampling


Availability: In stock