(1) For these regulations, a meter is inaccurate if it—
(a) over-registers the flow of gas by over 2% or, if the regulator determines in writing a smaller amount for this paragraph, that smaller amount; or
(b) under-registers the flow of gas by over 3% or, if the regulator determines in writing a smaller amount for this paragraph, that smaller amount.
(2) A determination is a disallowable instrument for the purposes of section 10 of the Subordinate Laws Act 1989 .