Name the instrument used for determining the purity of a sample of milk.

Answer the following question on one sentence : Name the device used to determine the purity of a sample of milk.

What instrument is used to determine the purity of milk ?

The instrument used to measure the purity of milk is

The instrument used to measure the purity of milk is

Lactometers (used to determine the purity of a sample of milk) and hydrometers (used to determine the density of liquids) are based on the _______ principle.

Name the instrument used to determine the direction of magnetic field .