# The Wireless Telegraphy (Control of Interference from Ignition Apparatus) Regulations 1973, Regulation 5: Requirement


(1) The requirement hereinbefore referred to is that the apparatus shall be so designed, constructed, assembled and installed, and that such precautions shall be taken in relation to it (by means of the fitting of suppressors or otherwise) as to ensure that the field-strength, at any distance of not less than ten metres from the apparatus when it is used, as measured and computed in accordance with paragraph 5(3) and the Schedule hereto, of the electro-magnetic energy radiated at forty megahertz and at any frequency up to seventy-five megahertz does not exceed fifty microvolts per metre and at any frequency between seventy-five and two hundred and fifty megahertz does not exceed fifty microvolts per metre at seventy-five megahertz rising linearly with frequency to one hundred and twenty microvolts per metre at two hundred and fifty megahertz.
(2) For the purpose of this Regulation the apparatus shall be deemed to meet these requirements over the whole frequency range of forty to two hundred and fifty megahertz if it meets them at the following discrete frequencies; forty-five, sixty-five, ninety, one hundred and fifty, one hundred and eighty, and two hundred and twenty megahertz. To avoid interference from transmissions operating on these discrete frequencies each frequency shall be subject to a tolerance of plus or minus five megahertz.
(3) For the purpose of Regulation 3 the apparatus shall be deemed to meet these requirements if measurements for the purpose of type-approval and production conformity in type-approved equipment are carried out in accordance with the procedures set out in paragraphs 3.6 and 3.7 respectively of British Standard 833:1970.
(4) For the purpose of measuring and computing the field-strength of such electro-magnetic energy, the apparatus shall be tested by means of measuring apparatus of the description and having the physical and electrical characteristics and performance set out in Section 1 of British Standard 727:1967 “Specification for Radio-Interference Measuring Apparatus for the Frequency Range 0.015 MHz to 1000 MHz”, except that where the apparatus forms part of the engine of a road vehicle measuring apparatus having the physical and electrical characteristics and performance set out in Section 2 of British Standard 727:1967 may be used. The tests shall be made by the method and under the conditions set out in the Schedule hereto.

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Source: https://www.legislation.gov.uk/uksi/1973/1217/regulation/5 (the official version)
Page: https://openlegislation.uk/wireless-telegraphy-control-of-interference-from-ignition-apparatus-regulations-1973/regulation-5
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.