Real Time Access To Experimental Data Using Tablet Pc’s

A custom data acquisition system was developed for use in mechanics of materials and materials science laboratories. The new system allows students to observe the physical phenomena demonstrated in the experiment and individually manipulate and examine the experimental data on a real-time basis. In the past, students would gather around an apparatus and passively watch the experiment being performed. The data collected were then distributed and analyzed at a later time, away from the presence of the instructor. The problem with this approach is multifold. First, significant amount of time may have lapsed since the experiment and students have a difficult time associating the calculated results to the experiment itself. Second, some phenomena which occur during the experiment require data reduction to fully explain. Since that reduced data is not available at the time of the experiment it can not be fully explained by the instructor during the experiment. Finally, even if an ordinary data-acquisition system is used, students are forced to observe the “official” data being shown, instead of being given the option of exploring various data output. This can be particularly instructive in complex experiments with multiple measurements. The new system addresses these problems. It couples a computerized data acquisition system to twenty-one wireless Tablet PC’s. While the test is in progress, test data is transmitted in real time to each student’s Tablet PC. Custom software allows students to view graphs of the test data and manipulate the data as it is being collected. Students can view force-displacement curves, displacement-time or force-time, temperaturetime, compare the emerging test results with past results of varying test parameters, and write notes directly on the graphed data. The impact of using Tablet PC in the lab was assessed using directed student surveys. Survey results show that over 90% of students felt that using the Tablet PC’s helped them understand the physical significance of the experiment, and over 95% the students felt that the Tablet PCs helped them correlate the test data with the physical phenomena. This paper describes the data acquisition system, the custom software developed for this lab, example of some of the materials science experiments, and the pedagogical benefits of providing students with real-time access to experimental data.