1 An online laboratory in Optical Instrumentation: The Compound Microscope Authors:

Abstract OpenLab is a project created to provide an online environment that complements the traditional classroom and laboratory methods. The here-presented work is focused on an online Physics laboratory. Specifically, this is a self-learning material concerned with Optical Instrumentation and, as a first step, we have prepared an online-simulation content on the principles of the compound microscope. First, this framework provides an online test in order to establish the compound microscope arrangement as a combination of a objective lens and an ocular lens (simple eyepiece). Several simulations make use of simple parameters controlling the behavior of the compound microscope. Image focal lengths of the objective and the ocular lenses and the optical tube length may be modified in order to control the objective lateral magnification, position of the exit pupil and the field of view. Also the object-position tolerance in the optical system is handled. Multimedia simulations reproduce a direct observation and online tests check the geometrical characteristics of the compound microscope. Additionally, by using the intermediate image we apply the reticule basis. Some examples are employed to measure an object lateral size. Finally, the tutorial system allows determining the normal magnification of the compound microscope having a doublet as an eyepiece. In resume, this innovative web-based teaching strategy allows a 24 hours access to the laboratory, profiting from training without the presence of teachers. Index Terms Autonomous learning, online laboratory, optical instrumentation