Can someone explain Tropic Marin hydrometer chart?

Going Salty! Making and using Saltwater

Messzylinder und Präzisions-Aräometer/hy

Hydrometer

Tropic Marin Hydrometer (densímetro De Alta Precisão)

Tropic Marin HIGH PRECISION HYDROMETER, claim's it's super accurate and never needs calibrated., Page 4

6317 - Tropic Marin Syn-Biotic Sea Salt 25kg/750l - Bucket

Messzylinder und Präzisions-Aräometer/hy

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Curious salinity swing REEF2REEF Saltwater and Reef Aquarium Forum

Tropic Marin HIGH PRECISION HYDROMETER, claim's it's super accurate and never needs calibrated., Page 2

Temperature Corrections for Hydrometers by Randy Holmes-Farley

Glass Hydrometer (Am I Old School) REEF2REEF Saltwater and Reef Aquarium Forum