These requirements cover the investigation of air leakage through door assemblies and other opening protectives (hereafter also referred to as test sample) installed in wall openings where air leakage is intended to be controlled. The purpose of the test is to determine only the resistance of a test sample@ in the closed position@ to air leakage resulting from a specified air pressure difference applied across the surface of the entire opening protective. These requirements apply to complete door assemblies@ opening protectives@ or to gasketing systems intended for use with specific door or other protective assemblies. The test method includes air leakage tests and cycling tests to determine the rate of air leakage through a test sample in an as-installed condition. The results obtained by use of this test method are expressed in cubic feet per minute per square foot (m3/s per m2) of opening and are intended to develop data to assist authorities having jurisdiction@ and others@ in determining acceptability of a door assembly@ opening protective@ or gasketing system with reference to control of air movement through an assembly. A door assembly@ opening protective@ or gasketing system investigated by this test method is intended for installation and use in accordance with the Standard for the Installation of Smoke Door Assemblies@ NFPA 105. This test method shall not be used for such opening protectives that include an air leakage test method within the test standard. For example@ the Standard for Fire Tests of Through-Penetration Firestops@ UL 1479@ contains an air leakage test method for firestop systems and therefore shall not be substituted with this test method.