Meters (Certification) Regulations (Northern Ireland) 1998 No. 444

SCHEDULE 1 Authorised Manufacturers' and authorised repairers' tests and testing methods for alternating current watthour meters

Methods of accuracy test

4.  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.