  We present a new experimental method for measuring inner-shell ionization
cross sections of low-charged ions colliding with hydrogen gas target in a
storage ring. The method is based on a calibration by the well-known
differential cross sections of proton elastic scattering on nuclei. $K$-shell
ionization cross section of 1047(100) barn for the 95 MeV/u $^{58}$Ni$^{19+}$
ions colliding with hydrogen atoms was obtained in this work. Compared to the
measured ionization cross section, a good agreement is achieved with the
prediction by the Relativistic Ionization CODE Modified program (RICODE-M).
