The goal of this study was to find the absolute calibration of the LHC Beam Gas Interaction
monitors (BGIs). This calibration will be used during the 2011 run, but also to correct the
data registered in 2010 run, with old calibration. The calibration run has been performed
on the 5th of December 2010, using orbital bumps. The beam position has been measured
with Beam Position Monitors. Because the closest BPMs are many meters from the BGI
location, the beam position has been interpolated. Two-dimensional beam images were