The principle upon which a lactometer works is
Lactometer
is basically a hydrometer which works as per Archimedes Principle. And
Archimedes Principle states “any object partially or wholly immersed in a
liquid is buoyed up or lifted up by a force, which is equal to the weight of
the liquid displaced by the object”. Thus lower the density of milk, more the
lactometer sinks. Buoyant force is the force acting upwards to reduce the
actual weight of the object.