This repository contains various documents associated with understanding and improving our purity measurements in EXO-200. It contains: In Documents, some useful reference material. In MakeCSVList, the code for creating a comma-separated list of 2.6 MeV events and their energies. In MeasurePurity, the code that reads in a comma-separated list of events and outputs a purity. In Datasets, some already-produced comma-separated lists of events.