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:
May. 03, 2005
Filed:
Feb. 19, 2002
Keigo Banno, Aichi, JP;
Hideki Ishikawa, Aichi, JP;
Yoshikuni Sato, Aichi, JP;
Noboru Ishida, Gifu, JP;
Takafumi Oshima, Aichi, JP;
Keigo Banno, Aichi, JP;
Hideki Ishikawa, Aichi, JP;
Yoshikuni Sato, Aichi, JP;
Noboru Ishida, Gifu, JP;
Takafumi Oshima, Aichi, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
An ultrasonic-wave propagation-time measuring method and gas concentration sensor are disclosed in which a reception wave which has been transmitted and received by an ultrasonic elementis subjected to full-wave rectification in order to obtain a full-wave-rectified wave, which is then integrated by an integration circuitto obtain an integral value. A peak value of the integral value is held by a peak-hold circuit. As to detection of gas concentration, a threshold-level calculation sectionsets a reference value on the basis of the peak value, and a point in time when the amplitude of a reception wave having undergone full-wave rectification is judged by a comparatorto have reached the reference value is regarded as an arrival time. Subsequently, a gas concentration is determined on the basis of a period between the emission time and the arrival time.