What is Dynamometer:
A dynamometer is an artifact designed to measure the force and weight of objects from the elasticity of a spring or elastic spring. The word is formed from the Greek term dynamis which means ‘force’, and the term meter (metron) which means 'measure'.
Mechanical dynamometer and electronic dynamometer
Among its functions is:
- Measurement of the weight of bodies;
- Application in testing machines (measure penetrations of hardness, tensile force, etc.);
- Measure applied forces.
The traditional dynamometer was invented by Isaac Newton. This scientist applied the principles of Hooke's law of elasticity, according to which the stretch of a certain flexible or elastic material is directly proportional to the force exerted on it.
Originally, the dynamometer works with a hook at the lower end on which the object whose force or weight is to be measured is hung. Today there are scales that use this spring system, but they replace the hook with plates on which they place objects, which is why there is a tendency to confuse dynamometers with scales.
Mechanism of operation of the dynamometer and the
scales that equally apply Hooke's law.
- Properties of matter.
Parts of a dynamometer
A dynamometer is made up of the following parts:
- A spring or spring;
- A cylinder that houses the spring;
- Two hooks, each distributed to each end of the dynamometer:
- A hook that serves as a support or enclave;
- A hook on which force or weight is exerted;
- A scale of measurement in newtons, kilos, or both.
There are at least two types of dynamometers: mechanical and digital. Let's look at each of them.
- Mechanical dynamometer: these are traditional dynamometers, in the same line as that developed by Newton, based on a totally mechanical system. This dynamometer does not require power for its operation. It usually offers greater precision, since its range of difference is only 0.3%.
- Digital or electronic dynamometer: are those in which digital measuring instruments are used. Its mechanism is much more complex and requires energy sources for its operation, such as batteries or electric current.
Difference between dynamometer and balance
The dynamometer and the balance are different instruments, although they are often confused. The dynamometer measures the force and weight of objects while the balance only measures their mass. Certainly the weight is related to the mass of the object, but it varies according to the gravitational field while the mass does not.
Balances and dynamometers have different operating systems. Balances are devices with two equal arms that work by placing masses at each end, which allows their physical properties to be determined by comparison (weight and mass).
From left to right: column scale, Roberval scale and Bérarger scale.
The dynamometer, on the other hand, determines the force and / or weight of a singular object, which is nothing other than the force with which the object is attracted by the field of gravity. If gravity (force) varies, weight varies. For this reason, the dynamometer must be calibrated every time it is moved, unlike the balance.
All spring-based or spring-based weight measurement systems are actually dynamometers. All mass counterweight measuring systems are balances.