DORINA PURCARU*, CORNELIA GORDAN**, ION PURCARU *** , MARIUS NICULESCU*, VICTOR PROCA****, ADRIAN VINTILA **** *Faculty of Automation, Computers and Electronics University of Craiova 13 Al. I. Cuza Street, 200585 Craiova **Faculty of Electrical Engineering and Information Technology University of Oradea 1 Universitatii Street, 410087 Oradea ***VIG Impex, Craiova 20 C. Brancoveanu Street, 200233 Craiova ****Research, Development and Testing National Institute for Electrical Engineering – ICMET 144 Calea Bucuresti Street, Craiova ROMANIA dpurcaru@electronics.ucv.ro, cgordan@uoradea.ro, purcaruion@yahoo.com http://www.ace.ucv.ro, http://www.icmet.ro Abstract: An accurate training on measurement techniques and measurement system design can be obtained by carrying out real experiments with real electronic components and circuits. The measurement system presented in this paper performs the computer aided study of the bending stress sensor. This experimental system is very useful for engineering undergraduates because they can test the theoretical knowledge about measurement techniques, sensors and transducers, signal conditioning circuits, data acquisition boards, signal processing methods and computers (hardware and software). The bending stress sensor consists of four strain gauges connected in a full>bridge circuit, and it transforms the load or force into measurable voltage change. An instrumentation amplifier and a noise suppression circuit and amplifier are designed for conditioning the output voltage of the bending stress sensor. The computer aided study of this sensor imposes a data acquisition board with a microcontroller, adequate software and a friendly user interface. The procedure for strain gauge sensor study supposes the following four stages: assignation of the measurement points, plotting the transfer characteristic of the force transducer, computing some parameters of the force transducer (zero error, differential sensitivity, relative sensitivity), weighing some objects using the strain gauge sensors. The architecture and design considerations for signal conditioning module and data acquisition board are also presented in this paper. KeyWords: Undergraduates, experimental training, measurement system, bending stress sensor, signal conditioning circuit, data acquisition board, computer, user interface, procedure. In the last years the authors have devoted great attention to the different aspects of the educational activity, with particular emphasis to theoretical and experimental training of the undergraduates on measurement methods, measurement systems (architecture and working mode), real instruments (features and working principle), virtual instruments, useful tools (advanced software and hardware), distance learning [1,2,3]. Therefore a number of tools have been realized in order to gradually propose to the students meaningful aspects of advanced technologies. An overview of selected tools is presented in [1], in particular a tool that takes into account the peculiarities of the unknown signal and also the effect of the noise signal superimposed to the signal to be measured. Moreover, through the connection to a measurement system working in the lab, the remote user can have the sensation of “distant participation” [4]. This activity cannot replace a hands>on contact to the real measurement equipment; however such WSEAS TRANSACTIONS on ADVANCES in ENGINEERING EDUCATION Dorina Purcaru, Cornelia Gordan, Ion Purcaru, Marius Niculescu, Victor Proca, Adrian Vintila ISSN: 1790-1979 131 Issue 5, Volume 6, May 2009