Del. Code tit. 6, § 5105

In addition to the state standards provided for in § 5104 of this title, there shall be supplied by the State such “field standards” and such equipment as may be found necessary to carry out the provisions of this chapter. The field standards shall be verified upon their initial receipt and thereafter as often as deemed necessary by the Secretary by comparison with state standards. The specifications and tolerances for reference standard and field standard weights and measures shall be those as specified in Handbooks 105-1, 105-2 and 105-3 of the National Institute of Standards and Technology and supplements thereto, or in any publication superseding these publications.