ย Giulio Barbato,ย Alessandro Germakย andย Gianfranco Gentaย are professors of โExperimental Statistics and Mechanical Measurementsโ at Politecnico di Torino. Prof. Barbato and Germak worked for over twenty years at the Italian National Metrology Institute on Primary Force and Hardness Standards and in the field of Accreditation for the Italian Calibration Service.