CMS Luminosity Calibration for the pp Reference Run at $\sqrt{s}=5.02~\mathrm{TeV}$

The measurement of the integrated luminosity delivered to the CMS Experiment during the very first LHC proton-proton run at $5.02~\mathrm{TeV}$ center-of-mass energy is presented. The Pixel Cluster Counting method is used and the absolute luminosity scale calibration is derived from an analysis of Van der Meer Scans performed in November 2015. The overall uncertainty on the luminosity measurement is $2.3\%$. The time stability of such calibrations is also studied and taken into account for the final systematic uncertainty.