Monitoring of air tunnels in a cylindrical storage device using ECT tomography David Žurovec, Jakub Hlosta, Jan Nečas, Jiří Rozbroj and Jiří Zegzulka MATEC Web Conf., 263 (2019) 01008 Published online: 30 January 2019 DOI: 10.1051/matecconf/201926301008