To validate installation of new equipment or following a major maintenance operation, a fast mapping operation can be performed n order to qualify the heating and cooling phases. To achieve this, several temperature sensors are distributed on a horizontal plane in an empty chamber. This method gives information concerning process control (response time, measurement precision, etc.) and also allows the detection of significant faults. NB: even if acceptance mapping appears satisfactory, this does not in any way indicate the homogeneity of the thermal treatment applied to packaging.