In Situ Aerosol Instruments

Aerodynamic Particle Sizer
The Aerodynamic Particle Sizer model (3321) manufactured by TSI uses the principle of inertia to size particles. The size range of the APS is 0.5-20 microns aerodynamic with 52 size bins.

Aerodyne Aerosol Time of Flight Mass Spectrometer (TOF-AMS)
The Aerodyne Aerosol Time of Flight Mass Spectrometer (TOF-AMS) is an instrument manufactured by Aerodyne Research Inc. and is used to study the chemical and physical nature of aerosol particles online.

Cloud Condensation Nucleus Counter
A Cloud Condensation Nucleus Counter (CCNc) is an instrument designed to count the number of particles which will activate to form cloud droplets at a specific supersaturation.

Condensation Particle Counters
Standard optical particle counters are not able to measure particles much below 50nm. To count smaller particles still Condensation Particle Counters are used, and can count all particles down to 2nm (depending on specific model).

Differential Mobility Particle Sizer
The Differential Mobility Particle Sizer (DMPS) is an instrument designed to measure aerosol size spectra down to very small sizes. The UMIST DMPS currently measures particles from 3.5nm to about 470nm.

Hygroscopic Tandem Differential Mobility Analyser
The Hygroscopic Tandem Differential Mobility Analyser (HTDMA) is designed to measure size resolved aerosol hygroscopic properties, ie how an aerosol distribution responds to a change in relative humidity.

Optical Particle Counters
The Centre for Atmospheric Science has a number of Optical Particle Counters of different types. These instruments measure the intensity of light scattered by particles passing through a laser beam and relate this to particle diameter.
Particulate Soot Absorption Photometer and Multi-Angle Absorption Photometer
The MAAP and PSAP both measure black carbon mass loadings based on the optical absorption of particles collected on a filter substrate. However there are some important differences in how these two instruments operate.

Photo Acoustic Soot Spectrometer
The Photo Acoustic Soot Spectrometer measures aerosol absorption at three wavelengths without first collecting particles on a filter. Black carbon mass loadings can be derived from the absorption measurement. The PASS is especially suitable for making measurements in high aerosol mass loadings such as vehicle exhaust or smoke plumes.

Scanning Mobility Particle Sizer
The Scanning Mobility Particle Sizer is based on the principal of the mobility of a charged particle in an electric field and can produce aerosol spectra with a much higher temporal resolution than the DMPS, though the sampling statistics suffer.

Single Particle Soot Photometer
Manufactured by Droplet Measurement Technologies (DMT) the Single Particle Soot Photometer (SP2) is a new instrument for measurement of soot content in individual airborne particles.

WIBS3
The WIBS3 is an optical particle counter featuring a dual wavelength fluorescence spectrometer designed to detect and count primary biological aerosol particles.