Weighing scales are to measure the weight and the calculative mass of an object. Spring scales give the weight by gravity force against the force of the spring; on the other hand balancing scales give the measurements by comparing the weight of object to the weight of the mass or masses. Both types can be adjusted to get the appropriate results. These calculations can be in unit of force such as Newton or in unit of mass such as kilogram. The balancing scale will give the weight accurately doesn’t matter where the object has place or on which side it has been placed but the change in the unit of force can lead to an incorrect result. But in spring scale the result will be changed with the change in the place of the object.
There are two types of balancing scales, Mechanical balance devices and electrical balancing devices.
Mechanical balance also known as laboratory balance or beam scale was the first invented mass measuring balance device. Its traditional form consists of a turned horizontal lever with arm of same length and pan hanged with each arm to put the objects and unit on each side. The result will be accurate as the beam gets closed to the equilibrium.
The balance compares weight rather than mass but given the gravitational field the weight of an object is proportional to its mass so the standard weight used to labeled in units of mass.
Unlike spring-bases scale, balance give the accurate measurements of the masses and it do not get affected by the difference of gravitational field. A change in the power of the gravitational field caused by moving mass will not change.
The precise measurements will be ensuring if the balance’s fulcrum will be friction-free, by attaching a pointer to the beam which intensifies the divergence from the balance position. Resilience should be allowed in the air which does effect on the densities of the masses involved.
The fulcrum is consisting of sharp v-shape pivot in a v-shaped bearing. Center v balanced is still gives the most accurate results.
Come chemical balance also have dials, a hybrid design with some accuracy of beam and poise but the convenience of a dial readings.
Electrical balances have been divided into four kinds and they are microbalance, pendulum balance scale, and Symbolism.
Microbalances are being used to measure the weight of small objects and in show the results in grams.
Analytical balance is a scale to measure the mass of small object in sub-milligram range.
Symbolism scales can be seen in courts in the hand of lady justice. Its origin in ancient Egypt