Weighing scale
A device for measuring mass or weight using equilibrium.
A weighing scale or balance is a device used to measure weight or mass. These instruments are also known as mass scales, weight scales, mass balances, massometers, and weight balances. Scales and balances are widely used in commerce, as many products are sold and packaged by mass.
- type
- Measuring instrument
- earliest known use
- Reign of Sneferu, Egypt
- key principle
- Mechanical equilibrium using a lever with equal arms
- common variations
- Balance scale, spring scale, Roberval balance, decimal balance
Lore & Background
The balance scale is such a simple device that its usage likely far predates the evidence. What has allowed archaeologists to link artifacts to weighing scales are the stones for determining absolute mass. The oldest attested evidence for the existence of weighing scales dates to the Fourth Dynasty of Egypt, with deben balance weights from the reign of Sneferu (c. Carved stones bearing marks denoting mass and the Egyptian hieroglyphic symbol for gold have been discovered, suggesting that Egyptian merchants had been using an established system of mass measurement to catalog gold shipments or gold mine yields. Examples dating c. In China, the earliest weighing balance excavated was from a tomb of the state of Chu of the Chinese Warring States period dating back to the 3rd to 4th century BC, made of wood and using bronze masses.
Reader's Guide
The weighing scale, in its traditional form as a balance, was the first mass measuring instrument invented. It consists of a pivoted horizontal lever with arms of equal length and a weighing pan suspended from each arm. Unlike spring-based scales, balances are used for the precision measurement of mass as their accuracy is not affected by variations in the local gravitational field. A center beam balance will render an accurate measurement of mass at any location experiencing a constant gravity or acceleration. Variations on the balance scale, including devices like the cheap and inaccurate bismar (unequal-armed scales), began to see common usage by c. Even with all advances, all scales until the seventeenth century AD were variations on the balance scale. The standardization of the weights used was a considerable preoccupation of governments throughout this time. The weighing scale remains essential in commerce and science, with the center beam balance still one of the most accurate technologies available for calibrating test masses.
Did You Know?
- The earliest weighing balance excavated in China was from a tomb of the state of Chu, dating to the 3rd–4th century BC, and was made of wood with bronze masses.
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