Laboratory work that has been applied so far is more dominant in deductive laboratory work, but this type of laboratory work is not optimal in stimulating students' reasoning ability. So far, model-based reasoning studies on laboratory work have been substantial (especially in measurement and troubleshooting activities) and have not seen overall laboratory activity including the use of alternatives instrumentation such as Arduino and its sensor module. The study of model-based reasoning in laboratory work is necessary as a basis in designing effective laboratory work activities. This research used mix method research design. Model-based reasoning in deductive laboratory work was obtained by matching predictive patterns and observation results. Predictive pattern was obtained based on laboratory work theory and model based reasoning in measurement, then predictive pattern was matched with observation result of 50 physics education undergraduate student when doing deductive laboratory work on electrical concept. Each learner showed different reasoning that could be seen from the selection of problem solution steps or selected different revision. The result of this study suggested that the used of arduino in deductive laboratory work could stimulate students' reasoning abilities. Arduino instrumentation raised interesting problems that could motivated learners to solve problems with their own reasoning.