Simulated X-ray spectra of an AGN with line-of-sight column density Log(N_H) = 23 (solid black line) and Log(N_H) = 24 (dotted red line). The vertical regions denoted by S (blue), M (orange), and H (green) represent the different bands used in our two HRs and they correspond to the 0.3−1, 1−2, and 2−10 keV bands, respectively. The two spectra show extreme differences in the soft X-rays, particularly in the 2−10 keV band. Thus, HRs targeting this band are helpful in determining the column density of AGN.