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:
Apr. 22, 2008
Filed:
Apr. 12, 2005
Rihito Shoji, Osaka, JP;
Rihito Shoji, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In a gas sensor, at least three levels of current are supplied to a heating element successively in a step-like manner for a predetermined time period. An arithmetic unit receives both-end voltages of the heating element for the respective current after elapse of the predetermined time period and calculates temperature from the both-end voltage of the heating element obtained when the lowest current flows. Then, the arithmetic unit corrects the both-end voltages of the heating element using the calculated temperature, a zero-point correction equation and a sensitivity correction equation to obtain respective standardized output values. Subsequently, the arithmetic unit calculates humidity based on the difference between the standardized output values, and corrects the standardized outputs based on the calculated humidity and humidity correction equations. By this method, the arithmetic unit calculates concentration of detection target gas.