Aerosol particle charge and size analyzer
US4633714A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 1985 |
| Grant date | Jan 6, 1987 |
| Priority date | — |
| Expiry date | Aug 13, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/02836
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An instrument for analyzing the size and charge of aerosol particles employs a dual beam laser Doppler velocimeter to track the motion of a particle while subjecting the particle to a sinusoidal acoustic field and to a pulsed, high voltage electric field. The particle transmitting through the crossed beams of the laser Doppler velocimeter moves with an oscillatory motion due to the acoustic field and, if the particle is charged, it has a horizontal drift parallel to the electric field during the electric pulse. The phase lag of the particle's motion with respect to the acoustic field is measured to determine the aerodynamic diameter of the particle and the velocity and the direction of the drift relative to the polarity of the applied high voltage electric field is used to determine the magnitude and polarity of the electric charge of the particle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.