Metric conversion : Hearing, Ninety-second Congress, second session, on S. 2483, to provide a national program in order to make the International Metric System the official and standard system of measurement in the United States and to provide for converting to the general use of such system within ten years after the date of enactment of this act; [and] S.J. Res. 219, to establish a national policy relating to conversion to the metric system in the United States. February 29 and March 1, 1972.