This paper presents a testing bench which can be used with post-graduated students, for practical exercises of a course on fractional order systems, their modelling, simulation, identification, observation and control. This testing bench is constituted of an entirely isolated aluminium rod heated at one of its extremity. The large length of the aluminium rod permits to consider it as a semi-infinite media. That thus allows to demonstrate the existence of a fractional order transmittance linking the applied thermal flux and the temperature inside the rod.