A liquid DP flow sensor on straight pipe

To detect water and pesticide flow rate for variable-rate spray, a new type liquid Differential Pressure (DP) flow sensor was introduced in this paper. The main problem that we attempt to solve was on-line flow measurement, to know the flow each moment and adjust pesticide to a desirable flow in the spray system. This new DP flow sensor is composed of a straight pipe with two branch pipes (an upstream branch pipe and a downstream branch pipe) in two ends and a DP sensor. A pressure difference between the upstream branch pipe and the downstream pipe is detected and converted into a voltage signal by the DP sensor. This voltage signal is transmitted to a microprocessor to determine liquid flow rate. Using water as working fluid, the liquid DP flow sensor at a certain dimension has been tested at the temperature of 22.0°C.The experimental results have shown that the presented device is satisfactory to variable sprayer with the measurement errors less than 1%. This liquid DP flow sensor´s advantage is simple in structure.