{
  "url": "https://openlegislation.uk/measuring-instruments-regulations-2016/schedule-1E/paragraph-4.2",
  "json_url": "https://openlegislation.uk/measuring-instruments-regulations-2016/schedule-1E/paragraph-4.2.json",
  "legislation": "uksi/2016/1153",
  "legislation_title": "The Measuring Instruments Regulations 2016",
  "legislation_url": "https://openlegislation.uk/measuring-instruments-regulations-2016",
  "path": "schedule/1E/paragraph/4.2",
  "kind": "paragraph",
  "number": "4.2",
  "heading": "Effect of disturbances of long duration",
  "text": "Table 3\nCritical change values for disturbances of long duration\nDisturbance\nCritical change values in percent for meters of class\nA\nB\nC\nReversed phase sequence\n1.5\n1.5\n0.3\nVoltage unbalance (only applicable to polyphase meters)\n4\n2\n1\nHarmonic contents in the current circuits\n1\n0.8\n0.5\nDC and harmonics in the current circuit\n6\n3\n1.5\nFast transient bursts\n6\n4\n2\nMagnetic fields; HF (radiated RF) electromagnetic field; Conducted disturbances introduced by radio-frequency fields; and Oscillatory waves immunity\n3\n2\n1\nIn the case of electromechanical electricity meters, no critical change values are defined for harmonic contents in the current circuits and for DC and harmonics in the current circuit.",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "F",
      "label": "F1",
      "text": "Schs. 1A-1K inserted (E.W.S.) (31.12.2020) by The Product Safety and Metrology etc. (Amendment etc.) (EU Exit) Regulations 2019 (S.I. 2019/696), reg. 1, Sch. 27 para. 49 (with Sch. 27 para. 50(a)) (as amended by S.I. 2020/676, regs. 1(1), 2); 2020 c. 1, Sch. 5 para. 1(1)"
    }
  ],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/uksi/2016/1153/schedule/1E/paragraph/4.2",
    "retrieved_at": "2026-10-28T23:17:40.726189+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}