Dual-Probe Device for Agricultural Main Canals: Avoiding False Flow Calculations Caused by Downstream Reflux at Rectangular Weirs [Dayu Electronics]
Local technicians often lack installation experience, and various unpredictable field conditions frequently lead to installation difficulties. To address the common issue of channel reflux causing false flow data calculations, and how to avoid or limit such occurrences
Details are as follows:
Small agricultural water conservancy main canal: 0.88 km
To address the water reflux phenomenon in the irrigation channel, a dual-probe open-channel device was specifically designed
At the main canal site: the upstream channel is short, and the maximum flow rate is above 40 liters/second, so a rectangular weir is recommended.
When using the instrument for measurement, first calibrate the reference zero point, which is the distance from the probe to the zero level of the weir tank.
Probe 1 is installed upstream of the rectangular weir and calculates flow by measuring the water level height above the weir opening.
Probe 2 is installed downstream of the rectangular weir and determines whether the water is backed up or if reflux is occurring by measuring the downstream water level.
If Probe 2 detects reflux and the water level rises, the flow meter main unit stops calculating flow.
This is because at this point, the upstream water flow of the rectangular weir is already affected by the downstream reflux, resulting in false flow readings.
As shown in the figure above, installing and using dual-probe open-channel for measurement can effectively avoid erroneous measurements caused by downstream water reflux, eliminating false flow readings and also resolving the long-standing troubles of customers in various regions.