What Is the Definition of a Balance Scale?

Balance scales were the original method of measuring weight.

Balance scales were the first known type of scale, and they inspired the development of modern scales. A balance scale use the known weight of an object, originally wheat grain, to measure the weight of an object whose weight is unknown.

Characteristics

Unlike modern scales, which use gravity, electrical resistance or spring tension, the balance scale only uses the known mass of an object. Balance scales are traditionally T-shaped metal objects with plates hanging from each end.

Original Model

The earliest known balance scale was developed about 2,000 years ago in ancient Rome. This model was known as the equal beam scale, and featured metal pans on the arms of a device that was shaped like a T. Ancient Romans used the scale to measure produce, grain and other commodities for trading purposes.

Development

Customers became skeptical of the original balance scale because it was easy to tamper with the machine to cheat customers by secretly adding weight to one side of the scale. Spring balance scales were developed to solve this problem, and this model is the type of scale modern bathroom scales use.

References

• Made How: Scale
• Livestrong.com: What is the difference between a weight scale and a balance scale?