This document specifies methods for the testing and rating of dampers and valves used in air distribution systems with pressure differences up to 2 000 Pa. The tests incorporated in this document will address: leakage past a closed damper or valve (for classification see Annex C); casing leakage (for classification see Annex C); flow rate/pressure requirement characteristics; torque: (see Annex A); thermal transmittance: (see Annex B). The acoustic testing of dampers and valves is not included in this document. The tests specified above apply to the following: measurement of leakage past a closed damper or valve; measurement of casing leakage; determination of flow rate and pressure requirements; measurement of torque characteristics (see Annex A); measurement of thermal transfer characteristics to determine insulation properties (see Annex B). NOTE Certain aspects of the dynamic performance of dampers and/or valves are dependent upon the air distribution system to which they are connected and are, therefore, difficult to measure in isolation. Such considerations have led to the omission of these aspects of the dynamic performance measurements from this document. Also, in common with other air distribution components, the results from tests carried out in accordance with this document may not be directly applicable if the damper or valve is situated in an area of non-uniform flow.