This page contains the raw calibration data and analysis tools used to characterize the contribution of ion and thermal leakage to the instrumental background of the Cassini INMS as discussed in the supplement to Waite et. al. 2017. The raw data was generated through a series of laboratory experiments with the Cassini INMS Refurbished Engineering Unit (REU). The experimental parameters for these measurements were designed to approximate the conditions seen during the E21 flyby of Enceladus. The analysis code is used to extract the raw data and organize it according to measurement type. The integrated results are presented in the spreadsheet file.