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:
Sep. 14, 1999
Filed:
Sep. 22, 1997
Nobukatsu Arai, Ushiku, JP;
Takehiko Kowatari, Kashiwa, JP;
Kaoru Uchiyama, Oomiya-machi, JP;
Izumi Watanabe, Hitachinaka, JP;
Shinya Igarashi, Naka-machi, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Car Engineering Co., Ltd., Ibaraki, JP;
Abstract
In a thermal type flow meter having a temperature compensating bridge circuit, the temperature compensating bridge circuit includes a heating resistor, a temperature compensating resistor and a plurality of resistors each having a fixed resistance. The heating resistor and the temperature compensating resistor are supported by a support member in an air flow passage, and the support member is formed by a material having a small temperature coefficient .DELTA..lambda. of thermal conductivity between -0.06 and 0.06 w/m.multidot.k.sup.2. The absolute value of the output error of the flow meter is reduced as a result of variation of the flow quantity or flow velocity of intake air and the intake air temperature.