NOTE: The specific gravity is temperature dependent. With increasing temperature the specific gravity decreases. Therefore, the measured water temperature should be 25 °C / 77 °F to obtain a correct result.For an exact, reliable measure of the specific gravity, we recommend to use the Tropic Marin® High Precision Hydrometer.

• Fill the measuring cylinder with maximum 400 ml saltwater (water temperature = 25 ° C / 77 °F).

• The hydrometer should be dry and clean.

• Gently place the hydrometer into the water until it floats freely.

• Now read the specific gravity on the blue part of the scale of the hydrometer at the level of the water surface - NOT at the level of the meniscus, which is creeping higher at the edges!

• To avoid any distortion of future measurements, rinse the measuring cylinder well with fresh tap or reverse osmosis water to remove salt residues after each use.
  

  Tropic Marin® High-Precision Hydrometer:

• Maximum deviation: 0.001 at 25 °C / 77 °F

• Scale from 1.021 à 1.031

• Resolution: 0.0001

• Recommended range: 1.025 to 1.027 (at 25 °C / 77 °F)