Digital Scales - How They Work

In this article we discuss how scales work, the difference between spring scales and balances, and provide some examples of how spring scale technology is used in digital scales in the consumer market.

Scales measure the mass or weight of an object. There are two types of scales. A spring scale uses a spring to detect how much weight is pulled. On the other hand, a balance scale uses a horizontal lever to compare an unknown weight to a standard weight.

A balance calculates the mass of an object by comparing it to an already known weight. On the other hand, a scale measures the force exerted on a mass by the Earth's gravity. It then converts that force into a number that shows the object's mass. We typically say that a scale measures weight, but we are actually measuring mass. If you are having trouble understanding how scales measure mass, picture this scenario: because the Earth's gravitational field is different than the moon's gravitational field, if you weighed yourself on a scale in your home and on the moon you would get two very different readings. Astronauts float in space because the gravitational pull exerted upon them is much smaller.

Spring scales can stretch or compress. For example, a scale that measures the weight of fruit stretches while a spring scale in a bathroom scale compresses. Spring scales are calibrated to display the force of gravity on an object. In the United States we use pounds to measure this. In other countries they use the metric system.

Spring scales have a possible source of error that balance scales do not. Because the elasticity of the spring can vary because of temperature, the spring must be made of temperature compensated material or be used in an environment where the temperature is constant. This is particularly important for commercial applications where spring scales are commonly used. Spring scales can measure products as light as feathers and as heavy as tractor-trailers.

A large consumer market has opened for spring scales that measure your weight. We used to find only analog scales in the bathroom, but electronic scales are more common now. Electronic scales are simply a variation of spring scale technology. In order to get an electronic reading, a strain gauge measures the deflection of a beam that supports the unknown weight. The strain gauge is a length sensitive piece of electrical resistance.

Electronic scales are more commonly referred to as digital scales. Sales of electronic scales in the home have increased. We are, after all, a society obsessed with appearance and thinness. In addition, as a culture we have a genuine health problem regarding obesity and it's important for people to regularly measure their weight.

The best bathroom scales have body composition monitors and more than one sensor so that they can be as accurate as possible. Bathroom scales also have programmable memories so that you can gauge your progress as you diet and exercise. In addition, if you have many family members trying to reduce their weight, the scale can remember the changes in each person's weight.

Anne Clarke writes numerous articles for Web sites on gardening, outdoor recreation, fashion, and home decor. Her background also includes teaching, gardening, and electronics. For more of her useful articles on digital scales, please visit Digital Scales, supplier of interesting and useful articles on the subject.

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