The system of weights and measures in customary use in the United States and the metric system of weights and measures are jointly recognized, and one or both of these systems must be used for all commercial purposes in the State. The definitions of basic units of weights and measures, the tables of weight and measure, and weights and measures equivalents published by the National Institute of Standards and Technology are recognized and govern weighing and measuring equipment and transactions in the State.
S.C. Code § 39-9-40