Question

On which pricipal lactometer and hydrometer are based state the principal

Answer 1

Operation of the hydrometer is based on Archimedes' principle that a solid suspended in a fluid will be buoyed up by a force equal to the weight of the fluid displaced. Thus, the lower the density of the substance, the farther the hydrometer will sink.

Answer 2

Both are based on archimides principle.
Lactometer is a device used for finding the purity of a milk sample. It works on the principle of Archimede's principle that a solid suspended in a fluid will be buoyed up by a force equal to the weight of the fluid displaced. If the milk sample is pure, then the lactometer floats on it and if it is adulterated or impure, then the lactometer sinks.
The point at which the surface of the liquid touches the stem of thehydrometer correlates to specific gravity. ... The hydrometer makes use of Archimedes' principle: a solid suspended in a fluid is buoyed by a force equal to the weight of the fluid displaced by the submerged part of the suspended solid.
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