3.8 Force Meter
A force meter is a scientific instrument that measures force. It is also called a newton meter or a spring balance. Nowadays, digital force meters are also available. We have already learnt about mechanical and electronic balances; they measure the mass of objects in kilograms or its multiples. A force meter, on the other hand, measures force directly in newtons (N).
An ordinary force meter has a spring inside it. The upper end of the spring is attached to a handle. A hook is attached to the lower end of the spring to hold the object. A pointer is also attached to the spring at its upper end. A scale in newtons is provided along the spring such that the pointer coincides with the zero of the scale when nothing is hung from the hook.
The object to be weighed is hung from the hook. The mass of the object causes the spring to compress. The pointer indicates the weight of the object. Some force meters are based on the stretching of the spring when a load is hung. In this case, the pointer is attached at the lower end of the spring.
In some spring balances, the scale measures the mass, which can be readily converted into newtons by multiplying the mass in kg by g = 10 m s⁻².
A digital force meter measures directly the weight of the object in newtons.
lightbulbDo You Know? The weight of a 100 g mass is 1 N.