Development of a new in-water-phantom graphite calorimeter for the measurement of absorbed dose to water in medium energy x-ray beams Massimo Pinto, Maria Pimpinella, Antonio Stefano Guerra, Iordana Astefanoaei, Maurizio Quini and Maria Pia Toni Published online: 07 October 2013 DOI: 10.1051/metrology/201305009