The specific gravity 60/60°F scale compares the relative density of a given liquid with that of water, at 60°F (15.6°C). The instruments listed are similar to hydrometers included in ISO 650 and in the (now superseded) 1960 issue of British Standard 718.
Hydrometers adjusted at 60°F (15.6°C)
Compares the relative density of a given liquid with that of water