# Directive 2014/32/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of measuring instruments (recast) (Text with EEA relevance), Division 4.3.1: The effect of an electromagnetic disturbance on an electrical energy meter shall be such that during and immediately after a disturbance:

Extent: E+W+S+N.I.

any output intended for testing the accuracy of the meter does not produce pulses or signals corresponding to an energy of more than the critical change value,
and in reasonable time after the disturbance the meter shall:
recover to operate within the MPE limits, and
have all measurement functions safeguarded, and
allow recovery of all measurement data present prior to the disturbance, and
not indicate a change in the registered energy of more than the critical change value.
The critical change value in kWh is m × U n × I max × 10 –6
(m being the number of measuring elements of the meter, Un in Volts and Imax in Amps).

---
Source: https://www.legislation.gov.uk/eudr/2014/32/annex/V/division/3/division/4/division/4.3/division/4.3.1 (the official version)
Page: https://openlegislation.uk/eu-directive-2014-32/annex-V/division-3/division-4/division-4.3/division-4.3.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.