Flow quantity test system for mass flow controller
US5394755A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1993 |
| Grant date | Mar 7, 1995 |
| Priority date | — |
| Expiry date | Sep 29, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/34
- WIPO fieldMeasurement
- WIPO sectorInstruments
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 i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.