Instrumental evaluation of traction machines sparking Nikita Kolobashkin, Beligma Dorzieva, Evgeniy Beyerleyn, Polina Tyuteva and Anatoliy Cukublin MATEC Web Conf., 141 (2017) 01034 Published online: 12 December 2017 DOI: 10.1051/matecconf/201714101034