NEN-EN-IEC 61243-3 is applicable to hand-held two-pole voltage detectors with their accessories (crocodile clips and detachable leads) to be used in contact with parts of electrical systems: - for a. c. voltages not exceeding 1000 V at nominal frequencies between 16 2/3 Hz and up to 500 Hz, and/or - for d.c. voltages not exceeding 1500 V.