Supplemental material to the article: "Capability of commercial trackers as compensators for the absolute refractive index of air," Precision Engineering 77, 46-64 (2022), https://doi.org/10.1016/j.precisioneng.2022.04.011. An archive file of research data which includes: a Python script which implements the calibration procedure of Section 3, together with the respective input experimental data for helium and argon gases. The script is generalized enough that any user supplying p, t_90, phi_i, and phi_f from a specific tracker setup can perform the calibration and establish absolute performance. experimental data for nitrogen gas, together with a Python script which reproduces Fig. 5. experimental data for water vapor, together with a Python script which deduces molar polarizability. This data and analysis are the basis for the reference value stated for A_R of water vapor and Fig. 6. experimental data for the refractive index of air. These data are the basis for the Edlen comparisons of Figs. 7 and 8. The datafiles also contain environmental records of p, t_90, t_dp, and x_CO2.