It is a device used to find out the mass of a substance by comparing it with known masses.


These are used mainly to weigh the chemicals accurately for the preparation of analytical reagents.


1. A beam.

2. Knife edges, screw nuts.

3. Stirrups.

4. Scale pans.

5. A pointer.

6. Ivory scale.

7. Rigid supports.

8. Wooden platform with levelling screws.

9. Handle.

10. Central vertical pillar.


1. Adjust the levelling screws to make the pillar vertical.

2. Release the beam by turning the handle. The pointer should swing to both the sides equally. Otherwise adjust it by turning the screw nuts at the end of the beam.

3. Place the object (to be weighed) in the left pan and standard weights (masses) from weight box, in the right pan.

4. Adjust the weights from the weight box so that the pointer swings to both the sides equally.


1. The beam of the balance should be arrested when not in use, and also before adding or removing weights.

2. The weights should not be allowed to lie on the pans or in the  wooden box.

3. The balance should not be loaded with a weight greater than the maximum it is constructed to weigh.

4. The substance should not be weighed hot.

5. The cabinet of the balance should be kept closed while a reading is taken.

6. Clean the balance after use.

7. Put a plastic cover over the wooden frame when balance is not in use.

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