Applies to portable voltage detectors with or without built-in power sources, to be used on electrical systems for voltages of 1 kV to 420 kV a.c. and frequencies from 15 Hz to 60 Hz. For the time being, it has been identified that : - For voltage levels up to 52 kV, the actual standard can be used in its entirety ; - For voltage levels above 52 kV, electric testing procedures are questionable from the point of view of their representativity and feasibility. For voltage detectors for use above 52 kV, manufacturers and customers should agree alternative electrical test arrangements, for example, electrical tests based on former national standards, until the publication of the second edition of this standard.