PC-Based System for Level Transducer Interfacing

Many applications rely on accurate readings from level transducers for a correct behaviour of complex systems. Large chemical and food industry plants employ large numbers of such devices which have to generate a correct behaviour and provide an accessible reading of the data. This paper presents an application for level measurement using appropriate signal conditioning and data acquisition hardware. We start by presenting the physical principles of level transducers and their classification. Signal conditioning, as an essential factor to obtaining correct readings is also highly regarded. The advantages of PC-based systems are then observed (compatibility, low-cost) along with the additional benefits brought by developing the software application in a graphical programming environment such as LabVIEW. We describe in depth the hardware system involved and the functionality of the written software. We add considerations regarding the performance of the overall system including hardware and software features. One interesting fact is that we have run the data aquistion application in an virtualized environment so we are able to make a performance-wise comparison among the virtualized and non-virtualized scenarios. The main output of the paper is the a software application for the measurement of the liquid level in a known-volume tank, which can be easily deployed across multiple computers due to its stand-alone characteristic. It is an appropriate tool for teaching and research projects and can easily be extended for the more stringent requirements of industrial tasks, such as reliability and compatibility with existing industrial systems.