Ohio Rev. Code § 1327.48: State reference standards of weights and measures.

Weights and measures that are traceable to the United States prototype standards supplied by the federal government, or approved as being satisfactory by the national institute of standards and technology, shall be the state reference standards of weights and measures, and shall be maintained in such calibration as is prescribed by the national institute of standards and technology. All working standards may be prescribed by the director of agriculture and shall be verified upon their initial receipt, and as often as found necessary by the director.