how to make model of lactometer on archimedes principle

Lactometer :-

It is based on the Archemedes' principle. When we put loctometer inside the liquid it experience buoyant force(weight of displace fluid). Hence measure relative density in the given scale of loctometer. Lower the density of liquid farther, the lactometer will sink.

It is basically a glass tube with a round shaped bottom containing a liquid of certain density inside it. The liquids will rise/fall inside the tube depending upon the pressure and depth.