Question

Describe the purpose, principle, and working of the Lactometer.

Answer 1

Purpose: Lactometer is an instrument to check the purity of milk.
Principle: Gravity of milk.

Construction:

1. Lactometer consists of a long graduated test tube with a cylindrical bulb.
2. The cylindrical bulb has graduated from 15 at the top and 45 at the bottom, which filled with mercury.
3. The test tube is filled with water.
4. The air chamber causes the instrument to float.
5. Mercury causes the lactometer to sink up to a proper level and to float in an upright position in the milk.
6. There is a thermometer inside the lactometer that extends to the upper part of the test tube.

Working:

1. The correct lactometer reading is only obtained at 60°C.
2. Lactometer measures the cream (density) content of milk.
3. Lactometer floats in milk if milk has more cream content.
4. The average reading of normal milk is 32.