# Meters (Certification) Regulations (Northern Ireland) 1998, Paragraph 2: Non-registration test

Extent: N.I.

Induction meters
(1) Induction meters shall be tested to ensure that when the current circuits are open and a voltage of 110% of the marked voltage is applied to the voltage circuits, rotors cease to rotate before completing one revolution.
Static meters
(2) Static meters shall be tested for non-registration by one of the following methods—
Method 1
(a) (i) When subjected to the test conditions specified in paragraph 2(1), the meter shall not emit more than one output pulse over the minimum test period determined in paragraph (ii);
(ii) the minimum test period (t) shall be computed by the formula:
t ge;480×106k.m.V.Imminutes where:
k = number of pulses per kWh emitted by the meter
m = number of elements
V = declared system voltage
Im = marked maximum current.
Method 2
(b) When static meters are fitted with inhibiting circuits, they may be tested for non-registration with a current, which is less than the threshold current in respect of a meter of that type, applied to the current circuits and a voltage of 100% of the marked voltage applied to the voltage circuits of the meters under test. Meters shall not emit more than one output pulse over a minimum test period (t) determined as follows—
t=126000V×I×k×pfminutes where:
V = declared system voltage
I = total current of all phases
k = number of pulses per kWh emitted by the meter
pf = power factor.

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Source: https://www.legislation.gov.uk/nisr/1998/444/schedule/3/paragraph/2 (the official version)
Page: https://openlegislation.uk/meters-certification-regulations-northern-ireland-1998/schedule-3/paragraph-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.