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 The instruments listed are similar to hydrometers included in ISO 650 and in the (now superseded) 1960 issue of BS 718. All hydrometers can be supplied with a UKAS certificate, certificate traceable to recognised national standard or statement of conformity. Please advise us prior to purchase if these are required.