The dynamometer, based on changes in the elasticity of a spring, can measure a force or calculate a weight.
A dynamometer is a tool that, based on changes in the elasticity of a spring with a certain calibration, allows you to calculate the weight of a body or measure a force .
This device was invented by Sir Isaac Newton ( 1643 – 1727 ) based on Hooke's law , taking the limits of measurement through the ability of a spring to stretch.
Characteristics of a dynamometer
With the spring protected inside a cylinder, the dynamometer usually has a pair of hooks (one at each of its tips). In the hollow type cylinder that is around the spring, on the other hand, the scale with the corresponding units appears. When a force is applied to the hook on the outside, the cursor at that end moves on the scale and indicates the value.
The dynamometer can have a specific design according to its application. This instrument can be used to weigh something and know its mass . In this case, the dynamometer must be calibrated every time it is moved due to changes in the link between mass and weight.
Stressed materials can also be measured through dynamometers to discover how much they deform. Even in the field of orthodontics, dynamometers can be used to establish what forces are applied in the treatment.
Another of their fundamental characteristics is that they have measurement ranges that go from a few Newtons to hundreds of kilonewtons.
Due to their characteristics, there are scales that are actually dynamometers.
Its operation
It is worth mentioning that the scale on which said measurement is carried out is indicated in units of force and the operation is quite simple. When hooking two weights or exerting a force on the outer hook, the needle on that side moves towards the outer scale and indicates the value of the force that has been exerted.
Its operation is related to the third law of physics explained by Newton, which says that every action has a reaction; Therefore, whenever two bodies A and B interact, with body A experiencing a force either through contact, magnetic or gravitational interaction, body B will experience at the same moment a force of similar magnitude but in the opposite direction.
Uses of the dynamometer
The dynamometer can have various uses , here we present some of them:
- Measure the weight of an object and also be able to obtain its mass. In this case, each time it is used, the dynamometer must be calibrated again because the relationship between mass and weight varies depending on the element to be weighed.
- Measure the specimens or their deformation in a tensile test or the penetration of a hardness test, applying it on laboratory testing machines .
- Measure forces applied during specialized treatment, mainly used in orthodontics.
Classification according to type
There are two types of dynamometers: mechanical or electronic . The first are the most used because they are estimated to be the most precise, presenting a maximum deviation of ± 0.3% of the load.
For example, Mecmesin mechanical dynamometers are suitable for solving practical issues without requiring electrical current. They are recommended especially for environments where there may be sparks or places where it is necessary to ensure safety .
Differences between the dynamometer and the balance
It is important to distinguish between the dynamometer, which measures forces, and the balance , which measures masses. In any case, some objects known as scales are actually dynamometers, since they operate using springs that extend or compress. That is the case of the kitchen scale that is used to weigh food.
To explain it more clearly, the dynamometer measures the weight of a body , which means that it marks the force with which the object is attracted by the field of gravity , while the scale measures the mass ; that is, the amount of matter that said body contains. If both measuring objects were taken to the top of a mountain or to the moon, the measurement marked by the dynamometer would differ in both places, while that of the scale would not.