The Spring Balance provides a method of mass measurement that is both simple and cheap. The mass is hung on the end of a spring and the deflection of the spring due to the downwards gravitational force on the mass is measured against a scale. The balance is a mechanical device used for measuring the weight or force of an object by opposing the force of gravity with the force of an extended spring. The key point to note is that weight is a force and spring balances are used to measure force. The Spring Balance is very accurate and useful.