Digital scales and balances are commonly used interchangeably, but they are in fact very different.
A scale measures weight, while a balance measures mass. While they do use the same principles for measuring, they vary greatly. In fact, a significant difference between the two is technology.
Digital scales use computerized technology to determine the weight of an object, while balance scales are manual, requiring you to physically place two objects together and compare the mass.
Let’s dive into these weighing instruments a bit more.
What is a digital scale?
Digital (or electronic) scales require the use of a microchip and electrical resistance to determine the weight of an object.
There are tons of different digital scales on the market. Truweigh offers a variety of digital scales in different sizes including ammo scales, jewelry scales, dental scales, dispensary scales, educational scales, fish scales, gunpowder scales, hair & beauty scales, hanging scales, home scales, kitchen scales, luggage scales, medical scales, and more.
Learn about how digital scales work here.
What is a balance scale?
Balances measure mass, or the amount of matter in something. Instead of an electronic microchip, they calculate based on the object placed on the platform of the balance.
Balances have a single bar resting on a pivot with two identically weighted platforms on both ends of the bar. Mass is measured when comparing the unknown mass to a known mass, a process that is not affected by changes in gravity.
To find the exact mass of the unknown, you simply adjust the amount of mass on the known side of the balance. There are three types of balances: the equal arm balances, unequal arm balances, and spring balances.
Three common types of balances
Equal arm balances
Equal arm balances mean that each end of the bar are equal distances from the pivot point, also called a fulcrum.
The fulcrum sits on the exact center of the bar, or at the center of gravity. This means the balance will be zero when the platforms are at equal levels, which happens when two objects of the same mass are on each platform.
Unequal arm balances
Unequal arm balances are the opposite of equal arm balances, so the fulcrum is not equidistant from platforms. Instead, one arm is shorter than the other.
You place the object you want to be weighed on the shorter end, while the known weights are moved along the longer arm until balance is obtained at an equilibrium.
Spring balances use the physics of a spring's elasticity to calculate the mass of the object. They have a coiled spring at one end and a hook at the other end to hold the object you want to be weighed.
The distance that the spring is stretched is proportional to the mass of the object that is being weighed. A pointer, as well as a graduated scale are attached to the balance to convert the distance the spring is stretched into a mass measurement.
Digital Scale vs. Balance
The main difference between a digital scale and a balance is that digital scales measure weight, while balances measure mass. Balance scales tend to be more precise, as they have been tried and true for centuries. They are also commonly used in doctor’s offices and in laboratories.
Digital scales are more commonly used at home for getting quick weight measurements. They are the most popular option for kitchen and body weight scales.