Introduction
principle
1. Principle of ultrasonic level measurement
The ultrasonic pulse emitted by the ultrasonic transducer propagates to the measured liquid surface through the transmission medium, and then returns to the receiving transducer through the sound transmission medium after reflection. Measure the time that the ultrasonic pulse propagates in the sound transmission medium from transmission to reception, and then according to the sound edge in the sound transmission medium, the distance from the transducer to the liquid level can be calculated to determine the liquid level.
2. The flow measurement principle of the weir tank
The larger the flow in the open channel with smooth circulation, the higher the liquid level; the smaller the flow, the lower the liquid level. The flow rate can be calculated by measuring the water level. The corresponding relationship between the flow and water level in an ordinary open channel is affected by the slope ratio of the channel and the roughness of the surface. A weir groove is installed in the channel to produce a throttling effect, so that the flow in the open channel has a fixed corresponding relationship with the liquid level.
Commonly used water measuring weirs are: Parshall flume, triangular weir, rectangular weir, etc. Parshall flume is preferred.
Features
●Built-in multiple algorithms, suitable for various standard water weirs
●Sturdy and stable ultrasonic sensor is suitable for harsh working conditions
●Chinese menu, more convenient to operate
●Probe replacement is convenient, spare parts replacement is more convenient
The blind area can be manually set to shield the interference signal near the probe
The transducer has built-in temperature sensor, real-time automatic temperature compensation
application
In many occasions such as sewage discharge, water conservancy projects, water supply diversion canals, and farmland irrigation, the waterways are open channels rather than pipes. The measuring instruments for the water flow of these channels are called open channel flowmeters. For a standard water weir tank, a high-precision liquid level gauge is installed at the fixed point of the weir tank, and the flow rate is calculated according to the water level-flow relationship of the corresponding buried tank. FU90 type is such a high-precision ultrasonic principle open channel flowmeter, which can display instantaneous flow/accumulated flow/liquid level at the same time.