Online Luminosity Measurements at CMS during LHC Run-3

The CMS experiment at the Large Hadron Collider (LHC) utilizes several detectors and counting methods that are independent of each other with the goal to obtain precision luminosity calibration with a relative uncertainty of about 1%. The instruments used for online luminometry include the pixel luminosity telescope and the fast beam conditions monitor, both using silicon sensors and operated independently of CMS, as well as the hadron forward calorimeter, and the drift tube muon detectors. These CMS sub-detectors measure the instantaneous luminosity for each LHC bunch crossing, using zero-counting, rate scaling or energy sum algorithms. The calibration constants, called visible cross section, are obtained for each detector with beam-separation scans analysed by the van der Meer method. In this talk, I will present the performance of the online luminosity detectors during the 2022 data taking period.