How Does a Digital Scale Work? The Technology Behind It

Digital weighing scales are fast becoming popular. This is because digital weighting scales are much more accurate than analog weighing scales and can display weight even with 1 decimal point accuracy. Modern digital scale can also come equipped with a host of other features such as BMI reading, body percentage reading, memory to store previous weight readings and many more. The digital screen also displays the exact weight in figures, thereby eliminating the need to carefully observe the dial as is the case with analog digital scales. The components of a digital weighing scale are smaller as compared to analog scales.

How does it work?

A digital weighing scale consists of four pegs which are slightly raised and  present at the corners. These pegs serve to distribute the weight of the person evenly. The basic component of a digital scale is load cell. Load cell is made of four strain gauges arranged in the form of wheat stone bridge. Strain gauge is a device made of metal tracks or foil present on printed circuit board or some other kind of backing. Strain gauge changes its resistance on application of strain. Thus, when strain is applied on the load cell, its resistance changes and this change in resistance is converted into an electrical signal. The number of load cells determine the load bearing capacity of a digital scale.

The signal conditioner of the machine converts the signal from the load cell into digital form. A microchip translates the data into numbers which appear on the screen of the machine. The weight reading can be displayed in any desired unit of weight.

Digital scales require batteries to run. Batteries provide electrical power to the load cell so that it is able to measure the change in resistance caused by the strain on it.

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