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:
Nov. 19, 1996
Filed:
Jan. 17, 1995
Chi K Lo, Fremont, CA (US);
Microsensor Technology, Inc., Fremont, CA (US);
Abstract
A compact and low fuel consumption flame ionization detector includes a precisely pored metallic disk or a silicon micro-machined diffuser plate through which the sample gas tube extends a minimum distance (less than 2 mm). The oxidant flows into the detector in a direction parallel to a plane of the diffuser plate, passes into a small cavity under the diffuser, and then passes through a large number of very small holes formed in the diffuser plate before encountering the sample gas flow at the end of the gas tube. A narrow diameter collector is closely spaced to the end of the gas tube. The direction of feeding the air and the diffuser plate (which acts as a baffle) provide laminar flow and eliminate the flicker noise which would otherwise occur due to the air flow inlet being located very close to the gas tube end. The FID is vertically compact and operates at a high electric field strength, exceeding 90 V/mm. The FID has a low fuel flow, typically 12-15 ml/min and therefore a low oxidant flow rate, typically 120-150 ml/min, advantageous to the operation of a portable gas chromatograph. The compactness of the FID also requires less electrical power to heat the detector to operating temperature, thus prolonging battery life.