专为测量封闭管道中含有一定固体杂质和气泡的液体和浆状物等介质的流量而设计。 DX90 series Doppler ultrasonic flowmeter is specially designed for measuring the flow of liquids and slurries in closed pipes containing certain solid impurities and bubbles. ，在安装和拆卸时都不必中断生产过程，它不与流体接触，因此具有不受管道污垢及堵塞影响和易于安装维护的特点;插入式传感器也可以在线安装，也不必中断生产过程，且能得到较高的信号强度。 It is characterized in that the outer clip sensor is installed outside the pipeline , and the production process does not have to be interrupted during installation and removal. It does not come into contact with fluid, so it is not affected by pipeline dirt and blockage, and is easy to install and maintain. It can also be installed online, without interrupting the production process, and can obtain a higher signal strength. 如非满管，请咨询我们，我们可以提供非满管产品和解决方案）。 It requires pipeline fluid to fill the pipeline (for non-full pipes, please consult us, we can provide non-full pipes products and solutions).
多普勒超声流量计适用于比较脏污的液体，具有优越的性价比，且独有可以测量极低流速流量。 DX90 series Doppler ultrasonic flowmeter is suitable for relatively dirty liquids, has superior cost performance, and uniquely can measure extremely low flow rates. For relatively pure liquids, a time difference ultrasonic flowmeter is recommended .
Doppler Ultrasonic Flowmeter Features
1. Excellent low flow velocity measurement capability, as low as 0.05m / s;
2. Extremely wide flow measurement range, high flow rate up to 12m / s;
3. Adaptive signal gain adjustment;
； 4. It can be installed online regardless of the external clip type or plug-in type ;
5. Simple operation, only need to enter the inner diameter to realize flow measurement;
6. Instantaneous flow and cumulative flow pulse output and flow alarm output;
7. Complete specifications, can provide various application solutions;
8. With national flameproof certification, many petrochemical users apply; very suitable for large-diameter sewage measurement.
利用了物理学中的多普勒效应，在任何流动的液体中存在的不连续都会使被反射的超声波信号产生频移 （也即信号产生相位差），通过测量相位差 ，即可测得流速。 The Doppler ultrasonic flowmeter uses the Doppler effect in physics. The discontinuity in any flowing liquid will cause the reflected ultrasonic signal to have a frequency shift (that is, the signal generates a phase difference). By measuring the phase difference To measure the flow rate. 。 Frequency shift is a linear function of flow rate. It is filtered by the circuit to produce a stable, repeatable and linear indication . Theoretically, these discontinuities can be suspended bubbles, solids, or interfaces due to fluid disturbances. ，主机处理信号并提供模拟输出供速度显示和体积流量显示及累积以及继电器输出。 The sensor generates and receives ultrasonic signals, provides data to the host , and the host processes the signals and provides analog output for speed display, volume flow display and accumulation, and relay output. In addition, the main unit includes a signal strength indicator to ensure satisfactory operation . 多普勒超声流量计就是基于多普勒超声测量原理，采用相位差方法来处理信号的。 DX90 series Doppler ultrasonic flowmeter is based on the principle of Doppler ultrasonic measurement and uses the phase difference method to process signals. 自动整形接收到的波形信号，它可以测量含衬里的管道，且对管道振动不太敏感。 It has a unique digital filtering technology and frequency modulation and demodulation technology. It automatically shapes the received waveform signal. It can measure the pipeline with lining and is not sensitive to pipeline vibration.
必须与液体的声阻抗（声波在介质中传播时的速度差异）有至少10%的差别。 The acoustic impedance of a sound wave reflecting material must be at least 10% different from the acoustic impedance of a liquid (the difference in the speed of sound waves as they travel through the medium).
The particles in the liquid must be large enough (greater than 100um) or contain air bubbles to cause longitudinal reflection of the sound waves.
When installing a plug-in sensor, there must be a long enough straight pipe section upstream and downstream of the installation location. Generally, 10D upstream and 5D straight downstream sections are required. D is the pipe diameter.