The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 16, 1977
Filed:
Nov. 03, 1975
William W Ho, Thousand Oaks, CA (US);
Ronald M Govan, Camarillo, CA (US);
Rockwell International Corporation, El Segundo, CA (US);
Abstract
A gaseous medium containing aerosols is drawn through a quartz sampling tube and a filter located therein, with the aerosols becoming entrapped on the filter. The filter is located at the geometric center of a microwave cavity, and the principal resonance of the latter is tracked with the aid of an adaptive electronic circuit. The time rate of change of the resonant frequency is a function of the rate of deposition of particulate matter on the filter, and principally of the liquid water content of those aerosols. Water in the vapor phase passes through the filter and does not affect the measurement; solid particulate does affect the frequency shift but in a second order manner and is readily compensated for after measurement of total aerosol mass deposited and the determination of the dielectric constant of the solid species therein. In a preferred embodiment a pair of microwave cavities is utilized to compare the resonant shift with the resonant frequency indicated for the same air sample after removal of the aerosol.