是以物理学中的多普勒效应为基础，根据声学多普勒效应，当声源和观察者之间有相对运动时，观察者所感受到的声频率将不同于声源所发出的频率。 The Doppler ultrasonic flowmeter is based on the Doppler effect in physics. According to the acoustic Doppler effect, when there is relative motion between the sound source and the observer, the sound frequency experienced by the observer will be different from the sound. The frequency emitted by the source. This frequency change due to relative motion is proportional to the relative speed of the two objects. Jinhu Dongxiang Doppler ultrasonic flowmeter can simultaneously record various parameters such as instantaneous flow, total flow, flow rate, pH value and downhole temperature in the pipeline.
在使用中产生误差的原因主要为3方面：(1)流量计本身存在的误差。 The reasons for the Doppler ultrasonic flowmeter's error in use are mainly three aspects: (1) The error of the flowmeter itself. (2) Flowmeter area / rate sensor installation error. (3) Reasons for current hydraulic conditions. The measurement error of Doppler ultrasonic flowmeter is mainly caused by objective reasons such as sensor installation and hydraulic conditions. In order to reduce the error, the position must be accurate when installing the rate / area sensor. At the same time, the liquid level of the pipe section to be detected should be above 6cm. The relative accuracy of the flow meter itself can basically meet the requirements. Jinhu Dongxiang proposed that the measurement principle of the Doppler ultrasonic flowmeter and the corresponding rate / area sensor can be applied to the current flow monitoring in the drainage pipeline. It can be more realistic with the graphs of various data. It can comprehensively reflect the current flow change law in the drainage pipeline, and can measure relatively real flow data. The Doppler ultrasonic flowmeter is equipped with corresponding data transmission and acquisition equipment, which can monitor the dynamics of the current drainage facility flow rate, and grasp the change of the water volume in the drainage pipe network in real time, combined with the drainage operation monitoring information management system, using GIS technology It can realize more flexible, accurate and real-time comprehensive analysis, optimized operation and scheduling modes, and create conditions for the realization of urban "digital drainage".
性能特点 Doppler ultrasonic flowmeter performance characteristics
Host display: Chinese / English display, can display instantaneous flow, cumulative flow, flow rate and other information
Data interface: standard RS-232C or RS-485
Data record: 65,072 data records can be stored (leading domestic technology)
Tube diameter range: Ф25 ～ Ф3048mm
Velocity range: 0.1m / s ～ 10.0m / s
Measurement accuracy: ± 0.5% ~ ± 2% FS
Suspended matter content: ≥100mg / L
Length of straight pipe section: 10D on the upstream side and 5D on the downstream side, 30D from the pump outlet (D: refers to the pipe diameter)
Installation: external binding or plug-in optional working temperature: host -20 ℃ ~ 50 ℃; sensor -40 ℃ ~ 82 ℃
Power supply voltage: AC85 ~ 265V can work, suitable for severe power supply voltage. Relay output: can set upper and lower limit alarms. Dimensions: 240 × 185 × 120mm