An electronic instrumentation course for non-electronic engineering students

International Journal of Electrical Engineering Education, Jan 2004 by Campilho, Aur�lio, Cardoso, Artur

Abstract

This paper reports on the implementation of a required course on electronic instrumentation for informatics engineering students. These students had proved in previous years to require a special approach, as their motivation for this subject was low. The course focuses on the basic concepts of Electronic Instrumentation, including analogue-to-digital and digital-to-analogue conversion and introducing the concept of instrument control. The course was organised in a set of lectures coupled with laboratory experiments, and a small project. To foster collaborative learning all the students work on the same laboratory experiments, simultaneously, organised in groups of two. The students' feedback on the course was more positive than in previous years, although not substantially so in terms of results. We feel that a change of attitude took place effectively, and that this could be attributed to the laboratory experiments using LabVIEW.

Keywords analogue-to-digital conversion; collaborative learning; electronic instrumentation; engineering education; LabVIEW

Electronic instrumentation courses are usually present in electronic engineering or similar degrees. However, the horizontal interaction with other engineering fields and the general use of electronic instruments often requires the introduction of such courses for non-electrical engineering degrees, such as in mechanical, civil, and informatics engineering. There are several engineering application fields that illustrate the impact of, or the interaction with electronic instrumentation. For example, in civil engineering transducers are commonly used in the stress analysis of buildings using measuring chains with complex networks of strain gauges. These are also often used in mechanical engineering for sensing strain in mechanical structures submitted to any kind of stress. The interaction with an immense number of analogue signals, and corresponding conversion to digital formats makes the computers widely used in processing digital data, intervening in various phases of data storage, processing and visualization. Thus, an informatics engineer plays an important role in conceiving and implementing the tools needed for the various data handling and processing tasks.

The course presented here was a required subject in an informatics engineering degree. However, the main concept can easily be applied to other non-electrical/ electronics engineering degrees. In this course we focused on the following topics: measurement and measurement errors; measurement methods and instrumentation; signals and signal conditioning; principles of current and voltage measurement; digital instrumentation; oscilloscopes; time and frequency measurement; transducers and measuring chains. The course contents are discussed in more detail below under the heading Course contents. The course was organised into three hours of lectures and one hour of tutoring per week, postulated on a classic teaching approach. Students proved unreceptive to and unmotivated by the subject in the first few years of the course. A move to a larger facility with more laboratory areas meant that a different approach could be taken to improve student performance.

We feel strongly that laboratory work is an important component of the formation of engineering students. As Edward4 has put it: 'well-designed (laboratory) work may be the cement that binds curriculum together and may make an invaluable contribution to the engineer's professionalisation'. We therefore based our approach on the premise that a good set of laboratory experiments using some computer interaction tightly coupled with concise lectures would be more motivating to the students. Since the overall length of classes could not be changed, the one hour of tutoring each week was changed into a two-hour laboratory session every two weeks. Simultaneously, the three hours of lectures per week were used for a more concise presentation of the subjects in a two-hour session combined with one hour of tutoring, consisting mainly of problem solving on the blackboard. The course objectives and teaching methodologies are presented in the following two sections respectively. A set of laboratory experiments was conceived, based on a standard electronic bench consisting of a signal generator, analogue oscilloscope, frequency counter, multimeter and a PC equipped with a data acquisition (DAQ) card. The timing and subject of the experiments were designed to afford a good synchronisation with the lectures. This was mostly a matter of scheduling and is commented on in more detail in the section on Teaching methodology. In the sub-section headed Laboratory experiments we present the set of four laboratory experiments that were developed for this course, covering fundamental concepts, basic principles of measurement, analogueto-digital conversion, signal acquisition and a final work which gathers all these aspects and introduces the concept of instrument control. A course website (www.fe.up.pt/~campilho/IE) provides access to learning materials such as handouts, computer programs and laboratory work guides. E-mail is used to enhance out-of-classroom communication between students and instructors.