Gives background information for Tests A: Cold (IEC 68-2-1), andTests B: Dry heat (IEC 68-2-2). Includes appendices on the effectof: chamber size on the surface temperature of a specimen when noforced air circulation is used; airflow on chamber conditions andon surface temperatures of test specimens; wire terminationdimensions and material on surface temperature of a component;measurements of temperature, air velocity and emission coefficient.