Particle sizing by electrical single particle aerodynamic relaxation time analyzer

Renninger, R.G.; Mazumder, Malay K.; Testerman, M. K.

doi:10.1063/1.1136581

Cited by 15 publications

(6 citation statements)

References 6 publications

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“…The principle of operation of the APS is shown schematically in Figure 20.13(a) which shows how the aspirated particles are focused into a narrow beam by means of an annular separate sheath of clean air, and the beam is introduced into the sensing zone through an acceleration nozzle. Renninger et al, 1981). The resultant two scattered light pulses allows for the determination of particle velocity on the basis of its 'time-of-flight' between the two beams.…”

Section: Optical Particle Countersmentioning

confidence: 99%

Direct‐reading Aerosol Sampling Instruments

2007

Aerosol Sampling

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Section: Optical Particle Countersmentioning

confidence: 99%

Direct‐reading Aerosol Sampling Instruments

2007

Aerosol Sampling

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“…The fringe separation is related to the laser wavelength and the angle of separation between the two beams. The distance between the fringes is given as follows (4) where, λ is the wavelength of the laser beam, and θ is the angle between the two laser beams. Fig.…”

Section: Introductionmentioning

confidence: 99%

“…To measure all particle sizes irrespective of their charge, a sinusoidal acoustic excitation is used to oscillate the particles [3]. A sinusoidal electric excitation measures only the particles which are charged, the uncharged particles traverse through the sensing volume without being effected by the electric field [4]. To measure both charged and uncharged particles a combined sinusoidal acoustic and a DC electric field were used [5].…”

Section: Introductionmentioning

confidence: 99%

Non-contact Measurements of Size and Charge Distributions of Submicron Particles using an ESPART Analyzer

Srirama

Stark

Zhang

et al. 2007

2007 IEEE Industry Applications Annual Meeting

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Characterization of size and electrostatic charge distributions of submicron particles with an instrument capable of in-situ and non-contact measurements is often necessary for many industrial and medical applications. These applications are related to thin film coatings, nanostructural assembly particles for energy conversion research and processing pharmaceutical fine powders, for example. The ESPART analyzer, which is used widely in the electro-photography industries for quality control of toner particles and, recently, in the lung deposition studies of inhaled particles for respiratory drug delivery, operates well in the size range of 1.0 to 20 µm in aerodynamic diameter and for an electrostatic charge range from zero to the saturation charge limit of individual particles with either positive or negative polarity. For measurement of submicron particles, however, several design changes in the instrument are necessary since both optical scattering and electrodynamic properties are significantly different with respect to those of larger particles. Advancement of the ESPART Analyzer with (1) a new optical geometry of Laser Doppler Velocimeter (LDV) for an efficient collection of scattered light from submicron particles, (2) a high frequency simultaneous excitation of the particles, as they cross the sensing volume of the LDV, with acoustic and electric drives and (3) an electronic signal processing system capable of analyzing LDV signals for determining relative phase shift and amplitude of the individual particle motion with respect to the excitation drives is reported. A description of the experimental design is presented.

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“…15 An acoustic or electrodynamic driving force of high frequency was applied to accelerate particles perpendicular to their a͒ Electronic mail: gerhard@iwt.uni-bremen.de main velocity component in an aerosol stream. Phase lag ͑sometimes also called relaxation time͒ measurements similar to our proposed method have been performed in an apparatus called E-SPART.…”

Section: Introductionmentioning

confidence: 99%

Periodic drag force and particle size measurement in a double ring electrodynamic trap

Göbel

Wriedt

Bauckhage

1997

Review of Scientific Instruments

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A CCD based approach to high-precision size and refractive index determination of levitated microdroplets using Fraunhofer diffraction Rev.A simple method to determine the size of a spherical particle in an electrodynamic trap from its dynamic behavior is introduced. Contrary to common usage of electrodynamic traps, gravity is not compensated completely. The resulting oscillatory trajectory is phase shifted with respect to the driving ac field of the trap. A light barrier setup is sufficient to determine the phase lag. An analytical solution is available in closed form to yield the particle diameter from the measured phase lag. Numerical trajectory simulations support this solution. Our method is independent of the optical properties of the particle. Only the viscosity of the surrounding gas and the particle mass density have to be known for data evaluation.

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Particle sizing by electrical single particle aerodynamic relaxation time analyzer

Cited by 15 publications

References 6 publications

Direct‐reading Aerosol Sampling Instruments

Direct‐reading Aerosol Sampling Instruments

Non-contact Measurements of Size and Charge Distributions of Submicron Particles using an ESPART Analyzer

Periodic drag force and particle size measurement in a double ring electrodynamic trap

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