very steep-front high-voltage impulses which may be chopped after a time as
short as 0.1–0.2 μs. This type of test does not require a very high measuring
accuracy, i.e. an uncertainty of a few per cent on the impulse crest is
acceptable. Details regarding impulse testing procedures of testing various
types of insulations are described in Chapter 8, section 8.3.1, with appropriate
references to national and international standards. Definitions of the prescribed
standard voltage waveshape to be used in testing can be found in Chapter 2,
Figs 2.23(a) to (c).