Design and Development of Wireless Electronic Flow Transmitter Using Circular IDC as Primary Sensor.

An Internet of Things (IoT) node-based nonintrusive, resilient liquid flow transmitter has been developed using a circular interdigital capacitor (IDC) as a primary sensor. A section of polyvinyl chloride (PVC) pipe is cut and a silicon tube of lesser diameter (compared with PVC pipe) is attached with the PVC pipe. A circular IDC is installed on the silicon tube and is used to convert the volumetric flow rate into corresponding capacitance. The change in capacitance with respect to the flow rate is nonlinear. Modified De Sauty bridge circuit is connected with the developed flow sensor to get the electrical output. To linearize the bridge output, three different linearization techniques, i.e., linear least square (LLS), genetic algorithm (GA), and artificial neural network (ANN) have been used and their statistical analysis is reported in this article. The best suited linearization technique (ANN) for the proposed sensor from the simulated result has been used in hardware implementation. This article proposes the IDC sensor access scheme design based on the IoT node and the transmission of the standard voltage signal 1–5 V using IoT node. The transmitted voltage and the received voltage have the same characteristic under the percentage error of ±0.5% of transmitted voltage. It has 0.286-pF resolution for measurement of liquid flow rate from 0 to 2000 litre per hour (LPH). This article highlights the theoretical analysis of the developed sensor to elucidate its working with maximum clarity. This sensor has been tested and its characteristics are thoroughly studied in the research workshop. Experimental results have proved that the wireless flow transmitter obeys linear characteristics and tuned well with theoretical equations based on the working principle. In addition, the proposed flow measurement is nonintrusive in nature as the circular IDC does not come in contact with the liquid flow, hence, increases the life span of the sensor. [ABSTRACT FROM AUTHOR]