CFR›Title 27›Chapter I›Part 30›Subpart C ContainsSections 30.21–30.25CorpusDaily eCFRDisplayed edition2026-04-24Last updated2026-04-24 Subpart C—Gauging Instruments Sections 30.21 § 30.21 Requirements. 30.22 § 30.22 Hydrometers and thermometers. 30.23 § 30.23 Use of precision hydrometers and thermometers. 30.24 § 30.24 Specific gravity hydrometers. 30.25 § 30.25 Use of precision specific gravity hydrometers. Previous B Subpart B—Definitions Next D Subpart D—Gauging Procedures