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. 20, 2016
Filed:
May. 23, 2013
Air Products and Chemicals, Inc., Allentown, PA (US);
Neil Alexander Downie, Hampshire, GB;
AIR PRODUCTS AND CHEMICALS, INC., Allentown, PA (US);
Abstract
There is provided a meter for measuring the mass flow rate of a gas, the meter comprising a conduit through which the gas flows in use, the conduit having a flow restriction orifice through which choked flow occurs in use, the flow restriction orifice dividing the conduit into an upstream portion upstream of said orifice and a downstream portion downstream of said orifice, the meter further comprising a sensor assembly including a first piezoelectric crystal oscillator in said upstream portion such that said first piezoelectric oscillator is in contact with said gas when the meter in use, a second piezoelectric crystal oscillator in said downstream portion such that said second piezoelectric oscillator is in contact with said gas when the meter in use, said sensor assembly being arranged: to drive the first and second piezoelectric crystal oscillators such that each of the first and second piezoelectric crystal oscillators resonate at respective resonant frequencies; to measure the resonant frequency of the first piezoelectric oscillator and the resonant frequency of resonant frequency of the first piezoelectric oscillator and the the second piezoelectric oscillator; and to determine, from the resonant frequency of the second piezoelectric oscillator, the mass flow rate of gas through said orifice.