Dataset of the comparison of the atomic clocks at INRIM between June 2021 and September 2022. Results discussed in Goti et al., Absolute frequency measurement of a Yb optical clock at the limit of the Cs fountain, Metrologia, 60, 035002 (2023). The involved atomic clocks are the Cs fountains IT-CsF2 and the Yb optical lattice clock IT-Yb1. Data is organized in folders. The data in the folder named 'INRIM_ITYb1-INRIM_ITCsF2-USO' is obtained making use of an optical-to-microwave chain. The data in the folder 'INRIM_ITYb1-INRIM_ITCsF2' is collected using an hydrogen maser as transfer oscillator. In the folders data is separated is one file per day. Data is reported as fractional frequency ratios in bins of 864 s. Timetags are reported in modified Julian date (MJD). A validity flag is given where 0 = invalid, valid otherwise. Each folder includes a yaml file with metadata required for generalized data processing as in [Lodewyck et al., 2020]. The Python package used for data processing can be found on github.

This work is supported by: the European Metrology Program for Innovation and Research (EMPIR) Projects 18SIB05 ROCIT and 20FUN08 Nextlasers, which have received funding from the EMPIR programme co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation programme.