Aerocet 531S Handheld Particle Counter

The Aerocet 531S is a s a full–featured, battery operated, handheld mass monitor or particle counter and completely portable unit. This unit provides particle counts or mass PM measurements as stored datalogged values, real-time networked data, or printed results.


This amazing unit simultaneously measures 6 mass concentration ranges (PM1, PM2.5, PM4, PM7, PM10 and TSP) and are displayed in mass mode. As well as five popular cumulative particle sizes (> 0.3, 1.0, 5.0 and10.0 microns) in count mode. With a tailored mass conversion The Aerocet 531S particle counts from eight size ranges which are converted to mass using a proprietary algorithm for typical-density aerosols. Accommodation for special particulate with different densities is provided through user–programmable “K-factors. The Aerocet 531S stores up to 6,257 records. These records can be viewed on the display, or transferred to a computer via USB or RS232. Our included Comet download utility makes file transfers easy. Data files can easily be imported into an Excel® formatted output. A temperature / relative humidity plug-and-play option immediately adds ambient temperature and relative humidity capabilities to displayed and logged data.


  • 2-in-1 Performance
  • Particle Counting & Mass Monitoring Modes
  • Cost Competitive
  • Keypad Selectable Sizes


  • Controlled Environments
  • Indoor Air Quality
  • Process Control
  • HVAC Applications
  • Filter Testing
  • Hospital & Clinics
  • Emission Sourcing
  • Environmental Surveys


Operating Principle
Counts individual particles using scattered laser light and calculates the equivalent mass concentration using a proprietary algorithm.
Mass Mode Performance
Mass Concentration Ranges: PM1, PM2.5, PM4, PM7, PM10, and TSP
Concentration Range: 0 – 1000 ug/m3
Sample Time – Mass Mode: 1 minute
Particle Mode Performance
Particle Size Range: Five channels—0.3, 1.0, 5.0 and 10.0 μm
Concentration Range: 0 – 3,000,000 particles per cubic foot (105,900 particles/L)
Sample Time – Particle Mode: 1 minute
Accuracy: ± 10%, to calibration aerosol
Sensitivity: 0.5 μm
Flow Rate: 0.1 cfm (2.83 lpm)
Light Source: Laser diode, 90 mW, 780nm
Power: 7.4V Li-ion battery pack—provides 20 hours of typical intermittent operation, up to 10 hours continuous use
AC Adapter/Charger: L-ion battery charger, 100-240 VAC, 50/60Hz, 0.2A
Communications: RS-232, USB
Particle Certifications: Meets or exceeds CE and ISO21501
Mass Certifications: Requires proper use of appropriate K-factors for material being measured
Display / Keyboard: 16 character x 4 line LCD / 7 key membrane type
Data Memory: 6,257 records
Power Supply / Charger: Yes
Software: Yes
Size: Height: 6.25” (15.9 cm) Width: 4.00” (10.2 cm) Depth: 2.12” (5.4 cm)
Weight: 2 lb – 32 oz (0.9 kg)
Operating Temperature: 0 ̊ C to +50 ̊ C
Storage Temperature: -20 ̊ C to +60 ̊ C
Supplied: Operation Manual
USB Cable
Communication Software (Comet)
AC Adapter / Battery Charger
Iso-kinetic Sample Probe
Carrying Case
Zero Particulate Filter
Optional: RH & Temperature Sensor (#G3120)
Flow Meter (#9801)
Portable Printer (#G3115)

Specifications are subject to change at any time