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. 14, 2004
Filed:
Mar. 13, 2003
Yuji Nakabayashi, Nara, JP;
Shuji Abe, Hyogo, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An input unit for receiving a signal from an oscillator corresponds to an ultrasonic wave received by the oscillator has an input impedance significantly smaller than an impedance of an inter-electrode capacitance in the oscillator. This arrangement allows the delay of timing of the received wave to be influenced by a change in the input impedance of the input unit than by a change in the impedance of the oscillator. Since the influence of the change in the impedance of the oscillator against the delay of timing of the received wave is reduced, a flow meter can measure a propagation duration of the ultrasonic wave accurately. More specifically, the flow meter can measure the propagation duration accurately regardless of a change of the inter-electrode capacitance of the oscillator by temperature, thus measuring a flow rate of fluid correctly.