Sgaramella, F; Miliucci, M; Bazzi, M; Bosnar, Damir; Bragadireanu, M; Carminati, M; Cargnelli, M; Clozza, A; Deda, G; De Paolis, L; Del Grande, R; Fiorini, C; Guaraldo, C; Iliescu, M; Iwasaki, M; King, P; Levi Sandri, P; Marton, J; Moskal, P; Napolitano, F; Niedźwiecki, S; Piscicchia, K; Scordo, A; Shi, H; Silarski, M; Sirghi, D; Sirghi, F; Skurzok, M; Spallone, A; Tüchler, M; Zmeskal, J; Curceanu, C: The SIDDHARTA-2 calibration method for high precision kaonic atoms x-ray spectroscopy measurements