National Measurement Act 1960

On and after the date from which the Australian legal units of measurement of a physical quantity are the sole legal units of measurement of that physical quantity, a reference in a law of the Commonwealth or of a Territory (whether the law was made before or after the commencement of this Act) to a unit of measurement of that physical quantity shall, if there is an Australian legal unit of measurement of that physical quantity of the same name and unless the contrary intention appears, be read as a reference to that Australian legal unit of measurement.