Differential pressure flow meter |
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| 申请号 | JP4461281 | 申请日 | 1981-03-25 | 公开(公告)号 | JPS57158515A | 公开(公告)日 | 1982-09-30 |
| 申请人 | Yokogawa Hokushin Electric Corp; | 发明人 | MINAGAWA MASATOSHI; OOKUBO AKIRA; | ||||
| 摘要 | PURPOSE:To correct gaseous pressure and a temperature error, by deriving a specific weight factor of gas, its saturation temperature and its specific weight correction factor in accordance with measuring pressure, obtaining a corrected specific weight, and deriving a flow rate by use of this specific weight. CONSTITUTION:A differential pressure detector 21 having a throttle mechanism, a temperature detector 22 and a pressure detector 23 are provided on a pipe 18 in which gas to be measured flows, and differential pressure DELTAP, a temperature T and pressure P are measured, respectively. Also, as to measuring pressure P, tables 24, 25 and 26 which have stored relation of a specific weight correction factor (a), a variation factor (b) of specific weight per a unit temperature, and a saturation temperature T' are provided, and signals (a), (b) and T' corresponding to the pressure P are outputted. Subsequently, a difference between a measured temperature T and a saturation temperature T' is operated 27, is multiplied 28 by the variation factor (b) of specific weight, a specific weight correction factor (c) is obtained, also it is multiplied 31 by the specific weight correction factor (a), corrected specific weight (gamma) is derived, and when a flow rate Q=alpha(DELTAP/r) is operated 32 by this corrected specific weight (gamma) and the differential pressure DELTAP, the flow rate is derived without gaseous pressure and a temperature error. | ||||||
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