This standard BS 718:1979 Specification for density hydrometers is classified in these ICS categories:
17.060 Measurement of volume, mass, density, viscosity
Five series of hydrometers for liquids between 600 and 2000 kg/m3 at 20°C and three petroleum sub-series at 15°C. Surface tension, dimensions, permitted errors, guide to purchasers, corrections for opaque liquids, method of use, density of water from 0°C to 40°C. Relative density (specific gravity) hydrometers previously specified but not retained.