BS 6840-17:1991

This standard BS 6840-17:1991 Sound system equipment is classified in these ICS categories:

• 33.160.30 Audio systems

This standard gives the characteristics to be specified, performance requirements and the relevant methods of measurement for electro-mechanical 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.

Since the response of the meter movement of such an indicator to the rapidly varying programme voltage is greatly dependent upon its dynamic characteristics, a standard for volume measurements shall therefore include a specification of these characteristics. The term “vu” (pronounced “vee-you” and written with lower case letters) is used to express volume in terms of vu above or below a specified reference level.

This standard does not deal with peak programme level meters which are the subject of IEC 268-10.

Defines the characteristics, methods of measurement, scale colours and standard scale markings, and requirements for a built-in or external attenuator for VU indicators (VU-meters) for use in recording studios and broadcast control rooms.