The purity of the milk is determined by Lactometer.
A lactometer is an instrument that is used to check for the purity of milk by measuring its density. An instrument to find out the content of the water in the milk or to test the richness of the milk is thus termed as 'lactometers'. The lactometer works on the principle of gravity of milk.
Product Description :
How to use it?
Put milk in the test tube.
Insert meter in the tube with bulb downwards.
Check reading on the meter.
Milk level up to red marking indicates pure milk.
Or Milk level above red marking indicates impure milk.
The deeper the meter sinks in the tube the more impure the milk is.