The pyrolysis process of polysiloxane thermosets is newly investigated by thermomechanical analysis (TMA). Curves obtained by TMA will be identified in confrontation with signals obtained by acoustic emission, which allows to record the occurrence of disturbances during the process. The pyrolysis process is very time consuming (in the order of tens of hours) and acoustic emission analysis requires a large sampling rate (in the order of MHz) and also large volumes of data are obtained, which must be precisely synchronized outside the analysis.