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:
Nov. 04, 1997
Filed:
Nov. 17, 1995
Luke D Hinkle, Townsend, MA (US);
MKS Instruments, Inc., Andover, MA (US);
Abstract
Apparatus for and method of measuring mass flow of a gas in a gas delivery system. The apparatus is adapted to be connected to a source of a gas. The apparatus includes a fixed-volume chamber in fluid connection with the gas source. A flow control device can be used to control the flow of the gas into the chamber. A transducer assembly comprises, in combination, a pressure transducer in fluid connection with the chamber, and a signal modifying network associated with the pressure transducer. The pressure transducer permits measurement of the pressure of the gas in the chamber and provides a first electrical signal representative of the pressure of the known volume of the gas. The signal modifying network modifies the first signal to produce an output signal which is proportional to PV/RT and thus directly represents the number of moles of the gas in the chamber. The apparatus is useful for calibrating mass flow controllers and the like.