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. 27, 2003
Filed:
Aug. 11, 2000
Yoshikuni Sato, Aichi, JP;
Keigo Banno, Aichi, JP;
Hideki Ishikawa, 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 which enables determination of accurate propagation time, a gas-pressure measuring method, a gas-flow-rate measuring method, and a gas sensor. A reception wave which has been transmitted and received by an ultrasonic element is shaped and integrated by an integration circuit to 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 resistance-voltage-division circuit sets a reference value on the basis of the peak value, and a point in time when the integral value of the reception wave is judged by a comparator to have reached the reference value is regarded as an arrival time. Subsequently, a gas concentration is detected on the basis of a period between the emission time and the arrival time. As to detection of gas pressure and flow rate, the gas pressure is detected on the basis of the peak value, and further, the gas flow rate is calculated on the basis of the gas pressure.