发明名称 |
METHOD AND DEVICE FOR MEASURING MASS FLOW OF GAS |
摘要 |
<p>A surface acoustic wave device for measuring the mass flow rate of a gas includes a surface acoustic wave delay line formed of a piezoelectric substrate and having a temperature coefficient of delay on the order of 10<-><4>/ DEG C. The substrate has disposed thereon a transmitting and a receiving interdigital transducer, the transducers being configured to have an operating frequency in the range of from 10MHz to 1000MHz. That portion of the substrate located between the transducers defines a propagation region and has a medium deposited thereon for absorbing a portion of the acoustical and/or electrical energy flowing thereacross. This absorbed energy increases the temperature of the propagation region over that of the surrounding ambient. A mass flow of the gas across the sensor will decrease its temperature and result in an upward shift in the resonant frequency. A suitable amplifier and resonant frequency detector may be coupled to the sensor for detecting the change in resonant frequency, thereby permitting mass flow rate measurement.</p> |
申请公布号 |
JPS6353422(A) |
申请公布日期 |
1988.03.07 |
申请号 |
JP19870203233 |
申请日期 |
1987.08.17 |
申请人 |
JOHNSON SERVICE CO |
发明人 |
JIYON GAABUIN BUREISU;TOOMASU SARUBUATOORE SANFUERITSUPO |
分类号 |
G01F1/68;G01F1/66;G01F1/688;G01F1/69;G01N29/00;G01N29/02 |
主分类号 |
G01F1/68 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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