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Particle Sizer/Counter

particle size counter
Linsey Marr, Professor of Civil and Environmental Engineering, is working on a sensor to detect particles given off in various scenarios, including 3D printing.

Aerosol monitors, commonly referred to as dust monitors, particulate monitors, light scattering laser photometers, are used to measure dust, smoke, mist, fume, condensates, and fog, and offer real-time, direct-reading results, which is quickly becoming an industry best practice in occupational hygiene, indoor air quality, and outdoor environmental fugitive emissions monitoring.

TSI particle counters and particle detectors contain instruments optimized for a variety of applications. They are often combined with particle sizers to measure size distributions.

APPLICATIONS

  • Atmospheric studies and environmental monitoring 
  • Combustion and engine exhaust studies
  • Indoor/outdoor air quality measurements
  • Inhalation toxicology studies
  • Aerosol research studies
  • Filter and air-cleaner testing
  • Power sizing

Aerosol particle sizers/counters in VTSuN lab provide particle size ranges from 1 nm to 20 micrometers for a variety of applications.

TSI 3936NL Scanning Mobility Particle Sizer (SMPS)

TSI's SMPS Spectrometer is widely used as the standard method to measure high-resolution size distribution of airborne particles spanning 4 - 700 nm. This particle sizer is also routinely used to make accurate nanoparticle size measurements of particles suspended in liquids. Capable of measuring high-resolution size distribution of aerosols spanning 4 - 700nm.  SMPS spectrometer sizing is a discreet technique in which number concentrations are measured directly without assuming the shape of the particle size distribution. The method is independent of the refractive index of the particle or fluid, and has a high degree of absolute sizing accuracy and measurement repeatability. 

TECHNICAL SPECIFICATIONS

  • High resolution data - up to 167 channels 
  • Broad size range - from 4 nm to 700 nm 
  • Fast measurements - complete size distributions in 16 seconds 
  • Wide concentration range from 1 to 107 particles/cm3   
  • Flexible set-up options; choice of water or butanol CPC fluid; choice of traditional or non-radioactive neutralizer 
  • Discrete particle measurement: works well for multi-mode samples independent of optical properties of the particles

TSI 3321 Aerodynamic Particle Sizer (APS) Spectrometer

The Aerodynamic Particle Sizer (APS) spectrometer provides high-resolution, real-time aerodynamic measurements of particles from 0.5 to 20 microns. These unique particle sizers also measure light-scattering intensity in the equivalent optical size range of 0.37 to 20 microns. By providing paired data for each particle, the APS spectrometer opens up exciting new possibilities for those interested in studying the makeup of an aerosol.

The APS spectrometer uses a patented, double-crest optical system for unmatched sizing accuracy. It also includes a redesigned nozzle configuration and improved signal processing. The result is greater small-particle sizing efficiency, improved accuracy of mass-weighted distributions, and virtual elimination of false background counts.

TECHNICAL SPECIFICATIONS

  • Double-crest optics produce high-quality measurements
  • Measures light-scattering intensity from 0.37 to 20 µm
  • Measures aerodynamic particle size from 0.5 to 20 µm

TSI 9306 Aerotrak Optical Particle Counter

Handheld Particle Counter for aerosols ranging from 0.3 to 25 μm.  The TSI 9306 offers the most features and flexibility for researchers interested in versatile handheld particle contamination monitoring. The Model 9306 features an ergonomic handle with thumb controls, for easy one-hand operation. The Model 9306 can generate Pass/Fail reports for ISO 14644-1, EU GMP Annex 1, and FS209E. Particle count data can be conveniently viewed on screen, downloaded, or printed directly to an optional external printer. 

TECHNICAL SPECIFICATIONS

  • 0.3 to 25 μm size range
  • 0.1 CFM (2.83 L/min) flow rate
  • Measures up to six channels of simultaneous data
  • Mass Concentration option (density parameter is user-configurable)
  • Removable, rechargeable Li-ion battery
  • Long life laser diode
  • Compatible with TrakPro™ Lite Secure and FMS 5 software packages
  • USB Cable, USB Storage Device and Ethernet data transfer
  • Data storage: 250 zones, 999 locations, and 10,000 samples 
  • Optional Temperature/RH sensor available

TSI DustTrak 8520 PM Monitor

The DustTrak 8520 PM Monitor is used for real-time measurement of PM1, PM2.5, or PM10.

TECHNICAL SPECIFICATIONS

  • Measure aerosol contaminants such as dust, smoke, fumes and mists
  • Battery operated, data-logging, light scattering laser photometers
  • Real-time mass concentration readings

EchoChem Analytics PAS 2000

The PAS 2000 detects ultrafine carbon aerosols in real-time. Using an Excimer lamp the aerosol flow is exposed to UV radiation. The Excimer lamp offers a high intensity, narrowband source of UV radiation. The wavelength of the light is chosen such that only the carbon aerosols are ionized, while gas molecules and non-carbon aerosols remain neutral.

The carbon aerosol particles emit electrons, which are subsequently removed when an electric field is applied.  The remaining positively charged particles are collected on a filter inside an electrometer, where the charge is measured. The resulting electric current establishes a signal, which is proportional to the concentration of Elemental Carbon and/ or Polycyclic Aromatic Hydrocarbons (PAH).  Photoionization aerosol sensor for particulate PAH.

TECHNICAL SPECIFICATIONS

  • Range : 0 to 4000 ng/m3 (conversion to particle-surface area is site-specific)
  • Sensitivity: ~ 10 ng/m3 (actual calibration is site-specific)
  • Lower Threshold: ~ 10 ng/m3
  • Response time: < 10 seconds (adjustable)
  • Sample gas: Built-in pump with flow rate controlled at 1 L/min
  • Operating temp: 40 to 104 ºF (5 to 40ºC)
  • Data Storage: 8000 data points (each data point consisting of: Time, Value)
  • Data Download: User-friendly PC-compatible graphical software used for downloading the collected data. Flat ASCII file output can also be generated for further analysis (e.g. Microsoft Excel format)

EchoChem Analytics Photoelectric Aerosol Sensor (PAS) 2000

Internal Highlight 1: Linsey Marr (co-PI)

Inward and Outward Effectiveness of Cloth masks, a Surgical Mask, and a Face Shield: Given the advice of public health agencies for the general public to wear face coverings and the paucity of knowledge about their effectiveness, the objective of this study is to evaluate the efficiency of cloth masks compared to a surgical mask and a face shield at blocking particles over a wide range of sizes. We first measure the filtration efficiency of materials under ideal conditions and then investigate both inward and outward protection efficiency of the materials when worn as masks on a manikin. We expect that efficiency on a manikin will be lower than in a filter holder due to leakage around the mask and that outward efficiency will be higher than inward efficiency due to differences in velocity of the particles as they approach the material. The results of this study will contribute to understanding how universal masking might reduce transmission of COVID-19 and other respiratory diseases. 

Figure 1: Material filtration efficiency of 10 mask materials as a function of aerodynamic diameter. The bandana appears twice because it was tested in both 1-ply and 2-ply configurations. Shading represents the standard deviations of triplicates.

particle size counter graph

Pan, J., Harb, C., Leng, W. and Marr, L. C. (2021) Inward and Outward Effectiveness of Cloth masks, a Surgical Mask, and a Face Shield, Aerosol Science and Technology, Ahead of Print.

Coming soon...