Our ASTM specific gravity hydrometers are calibrated at 60 °F and manufactured to the specifications of the American Society for Testing and Materials (ASTM).

• Calibrated for use at 15.5 °C/60 °F

Select the hydrometer that you need by matching the ASTM number shown. Specific Gravity, also known as relative density, is the ratio of the mass of a liquid to the mass of an equal volume of distilled water.