scope:

This standard applies to the measurement of partial discharge during test with alternating voltage, but general terms, definitions and requirements are usually also applicable for measurement of partial discharges during test with direct voltage. Some special characteristics of partical discharge measurements under direct voltage are given in a separate clause and necessary references are made throughout the text. This standard is intended principally as a general guide to the drafting of specifications for specific apparatus. The partical discharges which are considered in this standard are localized electrical discharges in insulating media, restricted to only a part of the dielectric under test and only partially bridging the insulation between conductors. Discharges mostly occur in the form of individual pulses, which can be detected as electrical pulses in the external circuit connected to the test object. However, a more continuous form may also occur, the so-called pulseless discharge. This form will normally not be detected by the measurement methods described in this standard. This standard deals mainly with electrical measurement of partical discharges, but some reference is also made to non-electrical methods.