Appropriate TTB officers may require the proprietor to furnish the necessary facilities and assistance to gauge or measure wine or spirits in any container or to examine any apparatus, equipment, container, or material on wine premises.
27 C.F.R. §24.40
Sec. 201, Pub. L. 85-859, 72 Stat. 1379, as amended, 1381, as amended, 1395, as amended, 1396, as amended ( 26 U.S.C. 5357 , 5366 , 5368 , 5555 )