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:
Jul. 10, 1990
Filed:
Oct. 25, 1988
Pedro Lilienfeld, Lexington, MA (US);
TRC Companies Inc., East Hartford, CT (US);
Abstract
A real time asbestos aerosol monitor and method are provided. An ambient air sample is passed through a first sensing zone where fibers in the sample are electrically aligned and oscillated as they are illuminated perpendicular to the fiber axes with high intensity laser light. The scattered light signal pulse train from a first detector is analyzed to determine the presence and size of fibers in the sample. The air sample is then passed through a second sensing zone including a hybrid electric/magnetic field to electrically align and magnetically oscillate asbestos fibers. The sample in the second sensing zone is illuminated perpendicular to the fiber axes, with the scattered light signal pulse train from a second detector being analyzed to determine whether each fiber detected in the first sensing zone is an asbestos fiber. Advantageously, clean air is circulated across illumination optical surfaces to protect against abrasive elements in the air sample. Zeroing and calibration are also provided.