Applies to two-pole voltage detectors to be used on electrical systems for nominal voltages not exceeding 1000 V a.c. and/or 1500 V d.c. and below 500 Hz (nominal frequencies). The detector types are classified as follows: - voltage class A: up to and including 500 V a.c./750 V d.c.; - voltage class B: up to and including 1000 V a.c./1500 V d.c. It also applies to supplementary functions such as phase indications, continuity checks and rotating field indications. Furthermore, it applies to accessories such as crocodile clips, contact electrode extensions and detachable leads.