Normalization of ISGRI spectrum is double than JEM-X
I used a simple power-law model and I notice that the normalization of ISGRI is about double than the two JEM-X, that are compatible. I repeated the test using files extracted by running the same version of OSA on lesta and results are different (higher flux in all instruments) but the discrepancy remains, see the notebook saxj1808-SpecIssue.ipynb