29.—(1) Every compartment shall be fitted with a fixed vertical dipstick guide tube.
(2) The tube shall be positioned so that the dipstick shall pass as nearly as practicable through the longitudinal and transverse centre lines of the compartment:
(a)this paragraph shall not apply in the case of compartments the use of which commenced before 1st July 1983; and
(b)if the tube is not so positioned, the dipstick measuring system shall not be used for trade after 31st December 1993.