The Weights and Measures (Local and Working Standard Capacity Measures and Testing Equipment) Regulations 1987

4.  Every working standard capacity measure—

(a) which is made of glass shall have been tested within 12 months before use;

(b) which is made of metal and

(i) is of 50 1 or less or 10 gal or less shall have been tested within 6 months before use;

(ii) is of more than 50 1 or 10 gal shall have been tested within 24 months before use.