TESTS OF HIGH-EFFICIENCY FILTERS AND FILTER INSTALLATIONS AT ORNL

摘要

High-efficiency filters are used in air handling systems as the primary means of minimizing the amount of radioactive particulate matter released to the atmosphere. The feasibility of measuring the filtration efficiency of "systems" containing such filters has been established at ORNL. Since the middle of 19 62 the efficiency of more than 650 systems has been successfully measured in situ using an aerosol of dioctyl-phthalate and a forward light scattering photometer. In addition, over 1500 new filters have been checked prior to being placed in ORNL stores stock. Tests have been made to determine (1) the linearity of the Naval Research Laboratory type photometer, (2) the precision of filter efficiency determinations, (3) the effect of prolonged exposure to aerosol on filtration efficiency, and (4) the effect of airflow rate on the efficiency of both efficient and defective filters.