The examples and perspective in this article may not represent a worldwide view of the subject. You may improve this article, discuss the issue on the talk page, or create a new article, as appropriate. Spring balances or spring scales calculate mass by first measuring weight by balancing the force due to gravity against the force on a spring, whereas a balance or pair of scales using a balance beam compares masses by balancing the weight due to the mass weighing balance principle pdf an object against the weight of one or more known masses.
The balance or pair of scales using a traditional balance beam to compare masses may read correctly for mass even if moved to a place with a different non-zero gravitational field strength. Scales and balances are widely used in commerce, as many products are sold and packaged by mass.
Very accurate balances, called analytical balances, are used in scientific fields such as chemistry. Although records dating to the 1700s refer to spring scales for measuring mass, the earliest design for such a device dates to 1770 and credits Richard Salter, an early scale-maker. Spring scales came into wide usage in the United Kingdom after 1840 when R.
Winfield developed the candlestick scale for weighing letters and packages, required after the introduction of the Uniform Penny Post. Postal workers could work more quickly with spring scales than balance scales because they could be read instantaneously and did not have to be carefully balanced with each measurement. By the 1940s various electronic devices were being attached to these designs to make readings more accurate.
A mechanical scale or balance is used to describe a weighing device that is used to measure the mass, force exertion, tension and resistance of an object without the need of a power supply. Types of mechanical scale include spring scales, hanging scales, triple beam balances and force gauges. This section does not cite any sources. Please help improve this section by adding citations to reliable sources.
Unsourced material may be challenged and removed. A spring scale measures mass by reporting the distance that a spring deflects under a load. This contrasts to a balance, which compares the torque on the arm due to a sample weight to the torque on the arm due to a standard reference mass using a horizontal lever. Spring scales measure force, which is the tension force of constraint acting on an object, opposing the local force of gravity.
They are usually calibrated so that measured force translates to mass at earth’s gravity. The object to be weighed can be simply hung from the spring or set on a pivot and bearing platform. By Hooke’s law, every spring has a proportionality constant that relates how hard it is pulled to how far it stretches.