Specifies procedures for test methods for the determination of the glass transition temperature of solid electrical insulating materials. They are applicable to amorphous materials or to partially crystalline materials containing amorphous regions which are stable and do not undergo decomposition or sublimation in the glass transition region. Changes from the first edition are as follows: - the standard has been completely revised from an editorial point of view and adapted to the state of the art; - a figure to demonstrate the dynamic mechanical analysis has been introduced.