6.—(1) Subject to paragraph (2) below, the apparatus shall be measured in the manner prescribed by clauses 6 and 7 of B.S. 800: 1983 or of B.S. 800: 1988 and shall comply with the relevant limits of interference prescribed in clause 4 of B.S. 800: 1983 or of B.S. 800: 1988, as the case may be, and, in relation to the testing of the apparatus and the limits of interference thereof, the apparatus shall comply with any other relevant procedures, requirements and specifications set out in B.S. 800: 1983 or B.S. 800: 1988, as the case may be.
(2) On and after 1st January 1990, apparatus which, by virtue of Regulation 4(1), is required to comply with Regulation 6, shall comply only with the relevant procedures, requirements and specifications of B.S. 800: 1988 and, in so far as such apparatus is concerned, the references to B.S. 800: 1983 in paragraph (1) above shall not apply.