6. Every filling instrument shall, before it is passed as fit for use for trade,–
(a)comply with a pattern in respect of which a certificate of approval remains in force at the time when such a filling instrument is so passed;
(b)have affixed to it the applicable descriptive markings relating to that filling instrument and have provision for a place for the application of the specified verification marks, in accordance with the requirements of Schedule 4; and
(c)subject to regulations 5(c) and 8, have successfully undergone initial verification testing and, as part of that testing, an accuracy class has been determined in respect of it: for the purposes of these Regulations, initial verification testing means testing of a filling instrument carried out by an inspector in accordance with the procedure specified in clause 5.3 (initial verification) of Part 1 of OIML R 61.