Katana VentraIP

Aerosol

An aerosol is a suspension of fine solid particles or liquid droplets in air or another gas.[1] Aerosols can be generated from natural or human causes. The term aerosol commonly refers to the mixture of particulates in air, and not to the particulate matter alone.[2] Examples of natural aerosols are fog, mist or dust. Examples of human caused aerosols include particulate air pollutants, mist from the discharge at hydroelectric dams, irrigation mist, perfume from atomizers, smoke, dust, sprayed pesticides, and medical treatments for respiratory illnesses.[3]

Not to be confused with aerosil.

The liquid or solid particles in an aerosol have diameters typically less than 1 μm. Larger particles with a significant settling speed make the mixture a suspension, but the distinction is not clear. In everyday language, aerosol often refers to a dispensing system that delivers a consumer product from a spray can.


Diseases can spread by means of small droplets in the breath,[4] sometimes called bioaerosols.[5]

as test aerosols for instruments, performing research, and testing sampling equipment and air filters;[13]

calibrating

to deliver , paints, and other consumer products in sprays;[14]

deodorants

for dispersal and agricultural application

for medical treatment of ;[15] and

respiratory disease

in systems and other combustion technology.[16]

fuel injection

People generate aerosols for various purposes, including:


Some devices for generating aerosols are:[3]

natural materials: fine dust, sea salt, or water droplets

inorganic

natural materials: smoke, pollen, spores, or bacteria

organic

products of combustion such as: smoke, ashes or dusts

anthropogenic

Physics[edit]

Terminal velocity of a particle in a fluid[edit]

For low values of the Reynolds number (<1), true for most aerosol motion, Stokes' law describes the force of resistance on a solid spherical particle in a fluid. However, Stokes' law is only valid when the velocity of the gas at the surface of the particle is zero. For small particles (< 1 μm) that characterize aerosols, however, this assumption fails. To account for this failure, one can introduce the Cunningham correction factor, always greater than 1. Including this factor, one finds the relation between the resisting force on a particle and its velocity:[36]

(AMS)

Aerosol mass spectrometer

(DMA)

Differential mobility analyzer

(EAS)

Electrical aerosol spectrometer

(APS)

Aerodynamic particle sizer

(AAC)

Aerodynamic aerosol classifier

(WPS)

Wide range particle spectrometer

(MOUDI)

Micro-Orifice Uniform Deposit Impactor

(CPC)

Condensation particle counter

Epiphaniometer

(ELPI)

Electrical low pressure impactor

(APM)

Aerosol particle mass-analyser

(CPMA)

Centrifugal Particle Mass Analyser

Aerogel

Aeroplankton

Aerosol transmission

Bioaerosol

Deposition (Aerosol physics)

Global dimming

Nebulizer

Monoterpene

Stratospheric aerosol injection

Archived 2020-01-21 at the Wayback Machine

International Aerosol Research Assembly

American Association for Aerosol Research

(see chapters on aerosol sampling)

NIOSH Manual of Analytical Methods