给出机电体积指示器的特性、性能要求和相关测量方法。“音量”的概念是为电子语音和音乐节目信号的大小分配数值的实用方法。 1991年9月的更正内容已列入本副本。

Gives the characteristics to be specified, performance requirements and the relevant methods of measurement for electromechanical volume indicators. The concept of 'volume' is a practical way of assigning a numerical value to the magnitude of electrical speech and music programme signals. The contents of the corrigendum of September 1991 have been included in this copy.