5. No person shall use for trade a filling instrument unless–
(a)it has been erected and installed in accordance with the requirements of Schedule 1;
(b)the requirements of Schedule 2 in respect of its use and manner of use are complied with; and
(c)in the case of a filling instrument of the description and maximum capacity set out, respectively, in columns 1 and 2 of Schedule 3, it is within the accuracy class specified for that filling instrument in column 3 of Schedule 3 or within an accuracy class of a higher level of precision than the specified class.