在哪能查到有关超声流量计的英文文章?（能翻译出2000字中文的,太少不行）急用谢谢了

在哪能查到有关超声流量计的英文文章?（能翻译出2000字中文的,太少不行）急用谢谢了

超声流量计是通过检测流体流动对超声束(或超声脉冲)的作用以测量流量的仪表.根据对信号检测的原理超声流量计可分为传播速度差法(直接时差法、时差法、相位差法和频差法)、波束偏移法、多普勒法、互相关法、空间滤法及噪声法等.超声流量计和电磁流量计一样,因仪表流通通道未设置任何阻碍件,均属无阻碍流量计,是适于解决流量测量困难问题的一类流量计,特别在大口径流量测量方面有较突出的优点,近年来它是发展迅速的一类流量计之一.优点:(1)可做非接触式测量; (2)为无流动阻挠测量,无压力损失; (3)可测量非导电性液体,对无阻挠测量的电磁流量计是一种补充.缺点:(1)传播时间法只能用于清洁液体和气体;而多普勒法只能用于测量含有一定量悬浮颗粒和气泡的液体; (2)多普勒法测量精度不高.应用概况:(1)传播时间法应用于清洁、单相液体和气体.典型应用有工厂排放液、:怪液、液化天然气等; (2)气体应用方面在高压天然气领域已有使用良好的经验; (3)多普勒法适用于异相含量不太高的双相流体,例如:未处理污水、工厂排放液、脏流程液;通常不适用于非常清洁的液体.
超声流量计的三种测速原理
1、时差法 测量顺逆传播时传播速度不同引起的时差计算被测流体速度.2、相位差法 测量顺逆传播时传播时由于时差引起的相位差计算速度.3、频差法 测量顺逆传播时传播是的声环频率差.
Ultrasonic flow meter fluid flow through the detection of ultrasonic beam (or ultrasonic pulse) effect to measure the flow meter.Signal detection based on the principle of ultrasonic flowmeters can be divided into propagation speed difference method (direct time difference,time difference,phase difference method and the frequency difference method),beam offset method,Doppler method,cross correlation,spatial filter method and the noise law.Ultrasonic flow meter and electromagnetic flow meters,as a result of meter flow channel is not set any obstacles pieces are unimpeded flow meter,flow measurement is suitable for solving difficult problems of a class of flow meters,flow measurement,particularly in large diameter have a more prominent the advantages of rapid development in recent years,it is one of a class of flow meters.Advantages:(1) do non-contact measurement; (2) for the measurement of free flow obstruction,no pressure loss; (3) measures the non-conductive liquid,obstruction-free measurement of the electromagnetic flowmeter is a kind of supplement.Disadvantages:(1) travel time method can only be used for clean liquids and gases; the Doppler method can be used to measure a certain amount of suspended particles and bubbles in the liquid; (2) Doppler measurement accuracy is not high.Application profiles:(1) travel time by applying clean,single-phase liquid and gas.Typical applications are industrial emissions and liquid:strange liquid,liquefied natural gas; (2) high pressure gas applications,the use of natural gas has been a good experience in the field; (3) Doppler method is not suitable for high-phase content of the two-phase fluids,such as:untreated sewage,industrial emissions and liquid,dirty process fluid; usually does not apply to a very clean liquid.
Three Principles for the Measurement Ultrasonic Flowmeter
1,the time difference measurement is good or poor propagation velocity of propagation time difference caused by different calculation of the measured fluid velocity.2,phase difference measurement is good or poor propagation time difference caused by the propagation phase as the calculation speed.3,frequency difference measurement is good or poor communication loop when the frequency of the sound propagation is poor.