发明名称 |
METHOD OF, AND APPARATUS FOR, MEASURING THE MASS FLOW RATE OF A GAS |
摘要 |
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. |
申请公布号 |
US2015107369(A1) |
申请公布日期 |
2015.04.23 |
申请号 |
US201314402450 |
申请日期 |
2013.05.23 |
申请人 |
Air Products and Chemicals, Inc. |
发明人 |
Downie Neil Alexander |
分类号 |
G01F1/32;G01F1/76 |
主分类号 |
G01F1/32 |
代理机构 |
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代理人 |
|
主权项 |
1. A method of measuring the mass flow rate of a gas through an orifice, the method using a first piezoelectric oscillator in contact with the gas upstream of the orifice and a second piezoelectric oscillator in contact with the gas downstream of the orifice and comprising;
a) driving the first and second piezoelectric crystal oscillators such that each of the first and second piezoelectric crystal oscillators resonate at respective resonant frequencies; b) measuring the resonant frequency of the first piezoelectric oscillator and the resonant frequency of the second piezoelectric oscillator; and c) determining, from the resonant frequency of the first piezoelectric oscillator and the resonant frequency of the second piezoelectric oscillator, the mass flow rate of gas through said orifice. |
地址 |
Allentown PA US |