N.C. Gen. Stat. § 81A-8: Standards of weights and measures.

Weights and measures that are traceable to the U.S. Prototype Standards supplied by the United States, or approved as being satisfactory by the National Institute of Standards and Technology, shall be the State primary standards of weights and measures, and shall be maintained in such calibration as prescribed by the National Institute of Standards and Technology. All secondary standards may be prescribed by the Commissioner and shall be verified upon their initial receipt and as often thereafter as deemed necessary by the Commissioner or his authorized agent. Complete record of the standards belonging to the State shall be maintained by the Commissioner. (1927, c. 261, s. 9; 1943, c. 543; 1949, c. 984; 1975, c. 544; 1991, c. 636, s. 22.)