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:
Mar. 07, 1995
Filed:
Sep. 29, 1993
Yoshihisa Sudo, Shiki, JP;
Minoru Ito, Inagi, JP;
CKD Corporation, Aichi, JP;
Abstract
In a flow quantity test system for a mass flow controller, a gas source for measurement is provided to supply gas for measurement. A cutoff valve for start of measurement is connected at its inlet port to the gas source for measurement and is connected at its outlet port to an inlet port of the mass flow controller. The cutoff valve for start of measurement is opened to flow the gas for measurement therethrough and closed to block the flow of the gas for measurement therethrough. A pressure gauge is provided to detect pressure of the gas for measurement appearing at the outlet port side of the cutoff valve for start of measurement. A microcomputer is provided to close the process gas cutoff valve and open the cutoff valve for start of measurement to change pressure detected by the pressure gauge. The microcomputer further closes the cutoff valve for start of measurement after pressure detected by the pressure gauge has reached predetermined pressure and measures lowering of pressure detected by the pressure gauge dependent on lapse of time after closing of the cutoff valve for start of measurement. Thereafter the microcomputer tests measuring precision of the mass flow controller in accordance with the measured lowering of the detected pressure.