# Meters (Certification) Regulations (Northern Ireland) 1998, Paragraph 4: Methods of accuracy test

Extent: N.I.

Method A test
(1) A long period dial test where the advance of a kWh display, which is part of or connected to a meter under test, is compared with the advance of a precision kilowatt-hour meter.
Method B test
(2) A short period test where the rate of advance of a meter under test is compared to the rate of advance of a precision kilowatt-hour meter.
Method C test
(3) A short period test where the actual rate of advance of a meter when tested under constant power conditions over a specified test period, is compared to the calculated rate of advance for those conditions.

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Source: https://www.legislation.gov.uk/nisr/1998/444/schedule/1/paragraph/4 (the official version)
Page: https://openlegislation.uk/meters-certification-regulations-northern-ireland-1998/schedule-1/paragraph-4
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.