LAr Purification and Purity Monitoring System at Wellesley College*

We report results from a 12-liter liquid argon test stand at Wellesley College. The system includes a single-pass liquid argon purifier, a double-gridded purity monitor to assess the electron lifetime, and a slow control and data acquisition system. This purifier will support ongoing detector R&D on charge and light readout technologies for future large-scale liquid argon time projection chambers (LArTPCs) such as Q-Pix and other cold electronics systems. We will present the design, construction, and operation of the test stand, along with initial performance results, including measured O₂-equivalent impurity level of 0.25 ppb, corresponding to an electron lifetime of 1.3 ms at a 500 V/cm drift field.