Experimental Study of Instrumentation and Control Devices on Fluid Flow Using A Digital Electric Flow Meter Based on A Programmable Logic Controller (PLC)

Abstract

This research aims to find out how to construct and design a PLC-based flow control device. to find out how to test and analyze the performance of the flow control device under various operating conditions. to find out how to assess the efficiency and accuracy of the control system in maintaining flow stability. The research was conducted at the Mechanical Engineering Workshop of Politeknik Negeri Manado from April to July 2025. The method used was laboratory-based experimentation, consisting of several key stages: problem identification, system design using PLC, selection and assembly of components such as flow meter, solenoid valve, and pump, programming control logic using ladder diagram, and direct testing of the system. Data collection was carried out by observing the system’s response to varying flow conditions, which were then analyzed to evaluate the efficiency, accuracy, and stability of the automated control system developed. The results showed that the developed flow control system operated automatically and stably. Under valve opening variations, the system recorded maximum flow rates of 15.01 L/min (fully open), 8.04 L/min (half open), and 4.67 L/min (quarter open). In the automatic drainage test using a solenoid valve, the system achieved an average flow rate of 5.94 L/min, draining 46 liters of water in approximately 7.75 minutes. These results demonstrate that the system successfully maintained flow stability, responded well to programmed logic, and is suitable to be implemented as a fluid flow automation prototype based on PLC.