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:
Dec. 24, 1996
Filed:
Jul. 31, 1995
Peter C Stroosnyder, Finksburg, MD (US);
Environmental Technologies Group, Inc., Baltimore, MD (US);
Abstract
In an apparatus for an air sample analysis, employing a dual polarity Ion Mobility Spectrometer (IMS), a method for stabilizing equilibrium conditions associated with the switching of the electric fields in the IMS cell comprises the steps of modulating a duty cycle of the electric field at the shutter grid located between the reactor region and the drift region of the IMS cell. During the switching of the electric fields at the cell, the open time of the duty cycle of the electric field at the shutter grid is extended. After the background polarity has been switched to the opposite polarity, the open time is returned to its normal value.