W. Va. Code § 47-1-2

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 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.

In addition to the state primary standards of weights and measures provided in this article, there shall be supplied by the state at least one complete set of copies of these standards, to be known as secondary standards; and such other weights, measures and apparatus as may be found necessary to carry out the provisions of this article, to be known as working standards. Such weights, measures and apparatus shall be verified by the commissioner, or at his discretion by his deputy or inspectors, upon the initial receipt of such weights, measures and apparatus and at least once in each year thereafter, the secondary standards by direct comparison with the primary standards, the working standards by comparison with the secondary standards. When found accurate upon these tests of secondary and working standards, the standards shall be marked as correct. The secondary standards shall be used in making all comparisons of weights, measures and weighing and measuring devices submitted for test in the office of the commissioner, and the primary standards shall be used only in verifying the primary standards and for scientific purposes.