Scales come in many different shapes and sizes, designed for many different uses. Large industrial scales are used to weigh heavy machinery; small pocket scales are used to weigh items less than 500 grams; jewelry scales are used to weigh precious stones; and there are plenty more. Depending on your needs, a simple spring scale may be the right choice.
One advantage to using a spring scale is the cost of the scale. Because of their simple, basic design, they are not expensive, although you may need to pay a little more if you plan on weighing heavier objects. After all, the scale is composed simply of a spring with a hook at one end and markings to indicate weight. Another advantage in terms of cost is that, thanks to its simple design, a spring scale does not require batteries or any other type of power to weigh objects, which many other scales do. The scale's simplicity also means that you will not find yourself replacing small, intricate and expensive parts.
A disadvantage of the spring scale is accuracy, or potential lack thereof. While you may find that a spring scale works well for making estimates of weight, it is difficult to get a very precise reading. Because calibrating a spring scale is time-consuming and difficult, manufacturers often settle for approximate markings on the scale. The amount of use a spring scale has received also affects the scale's accuracy because the spring has a tendency to relax over time. This relaxation will cause objects to appear heavier than they really are. Another consideration when it comes to accuracy is the aspect of support for the scale. Since the scale relies on the force of gravity to give an accurate reading, you must ensure that your spring scale is sturdily supported in a position perpendicular to the ground.
The convenience offered by a spring scale is a definite advantage. Its compact, cylindrical shape makes it easy to transport and store, and even larger spring scales meant for weighing heavier objects are not overly large. They also don't require a flat surface to rest on like many scales do, so you can use one virtually anywhere as long as you are not overly concerned with a strong support for the scale. The convenient nature of the spring scale makes it the scale of choice for a wide range of environments, from fishing boats to physics classrooms where storage and ease of set-up are important factors.