November 1, 2021

The galvanometer is a tool that is responsible for establishing an interesting study of the action of a magnetic field , initially it was based on an instrument that was oriented by the Earth’s magnetic field and provided the force to reset the compass needle. Today this action is produced by a magnet and originated in a coil by electric current.

Its name comes from the well-known Italian physicist Luigi Galvani, who discovered that when he applied electricity to the leg of a dead frog, it moved, as well as various and interesting demonstrations that served as the basis for another Italian physicist, Alejandro Volta, to carry out the discovery of the electric battery, a wonderful conquest for science.

It is important to note that other instruments such as the ohmmeter, the voltmeter and the ammeter are derived from the galvanometer .

What is a Galvanometer?

The galvanometer is a wonderful electrical measuring instrument that is used to calculate, discover and establish both the direction and the precise intensity of an electrical current.

Its operation is based on magnetic phenomena, formed by an electromagnetic and analog transducer that causes a certain deformation in the rotation of a pointer or needle, in demonstration of the electric current that flows through a coil.

This instrument was based on the electromagnetic field to supply the force that restores the needle in the compass. Later the use of magnets is included in the opposite way and that makes it independent of the Earth’s magnetic field, thus allowing them to work in any orientation.

What is a Galvanometer for?

This wonderful instrument is capable of detecting the existence of small electrical currents that are in a closed circuit, it can be adapted through calibration in order to measure the magnitude of said current.

The galvanometer was created at first to be used as a compass and to detect the magnetic field found on the earth, a long time later several researchers managed to discover the one that worked through magnets called a static galvanometer, thus allowing it to be used without the need for it. of the Earth’s magnetic field.

This is how it began to be used in the industrial area to determine the presence of electric current in different elements, however the first galvanometers had the disadvantage that other magnets that had magnetic fields were capable of influencing their operation.

How does a Galvanometer work?

The galvanometer is a very simple operating instrument , most of them work in a similar way, they are based on an indicator needle that is connected through a spring to the axis of a coil that has a rectangular shape and is suspended by the effect that cause two opposite poles of a permanent magnet.

The current to be measured begins to move through the coil and it begins to rotate on a vertical axis as it is in a magnetic field provided by the permanent magnet, causing the spring to unscrew.

This movement is equal to the current that passes through the coil and makes the movement of the needle equal. In this way, and with a suitable graduation, the needle indicates the value of the current.

It is a tool that can be used in different ways and the most important thing is that it is not necessary to have great knowledge to know how it works.

Uses of the Galvanometer?

As you already know, this tool is adjustable, precise and used to calculate the presence and power of the current. It can be used for different purposes both industrial and domestic , in fact in the market you can find some models that are very simple and can be used in a very simple way.

There are also those with a larger and more complex measurement scale, which allow to measure the intensity of the current in the industrial environment.

It can be used in recording devices avoiding that the current is less than necessary, as this causes the equipment to malfunction and if it exceeds it causes damage. It is also used in mechanical positioning units to measure the electrical current of a vehicle and even to measure the sound intensity of a musical equipment.

The irreparable damage that any device can suffer if it receives an electrical overload is considerable. With this useful tool you can prevent this from happening, controlling the current level that exists, either at home or in the work and industrial environment.

Galvanometer types

At present there is a great variety of galvanometers that can be classified according to the type of mechanism with which they work, they can be of thermal principle or magnetic principle.

  • Moving Magnet Galvanometer

This model is one of the most modern that exist . Its operation is very simple, it has an analog needle that is connected to the internal part of the device and that responds or indicates when there is the presence of electric current.

It presents a coil through which the current you want to calculate passes, causing a magnetic field and depending on its orientation it will attract and repel the magnet, in proportion to the intensity of the current.

  • Moving coil galvanometer

The operation of this is similar to that of the moving magnet galvanometer, but in this model the needle is attached to a small coil with a rectangular and moving shape. The current travels through it and is in the center of the magnetic field, caused by an immobile magnet.

This model is one of the most primitive and ancient that exist.

  • Concentric blade galvanometer

This model is called this way because it has blades, metal rings that capture and reproduce magnetic fields in a magnificent way. Placing several creates a very sensitive coil.

A blade that is in the center works as a mobile, while the other that contains the indicator needle moves when there is current presence.

  • Radial vane galvanometer

This model has two rectangular pieces or pallets that make up the core of the coil, one of them is mobile and the other is fixed. The mobile is magnetically rejected when there is current in the coil, by the paddle that is fixed, moving the indicator needle with it.

  • Thermal galvanometer

This model of instrument is responsible for measuring the passage of current through a completely different mechanism from that of magnetic models.

When an electric current passes through a conductor, the friction of electrons produces heat and the material usually expands. The passage of the current causes an extension by heating, a very thin conductor is attached to a common cylinder with the indicator needle, in which the elongation is completely corresponding to the passage of the current.

  • Plunger Galvanometer

This galvanometer has a fixed, hollow coil in which an iron core enters and leaves. The magnetic field that forms in the coil moves the plunger or iron core that contains the indicator needle.

With any of the galvanometer models you use, the result will always be reliable. They are devices that do not require special care , to keep it in good condition it is only necessary to prevent it from falling and coming into contact with water.

Characteristics of a Galvanometer

Most galvanometers today have the same parts , which greatly facilitate their operation and use, these are:

  • Moving coil: the current to be calculated circulates through it.
  • Spring: it is the one that achieves the union between the coil and the needle and makes the movement of the coil unite with the needle.
  • Needle: it is the piece that expresses the exact value of the current.
  • Permanent magnet: this magnet produces a magnetic field that causes the movement of the coil in an equal way to the current.
  • Scale: it represents the values ​​to indicate the magnitude of the current.

All these elements united in a perfect coupling will allow you to obtain the measurement of the passage of electric current when you need it and with complete reliability.

Importance of a Galvanometer

This tool is commonly used to measure and detect electric current, but over the years it has been refined, to include different uses in the same device .

The galvanometer symbolizes an extremely important scientific discovery , as it led to the precise measurement of electrical current.

If you still do not have this wonderful tool, do not wait any longer it will be very useful either at home or in your laboratory environment.

Dr. Loony Davis5
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Born and raised in Brussels in an English family, I have always lived in a multicultural environment. After several work experiences in marketing and communication, I came to Smart Water Magazine, which I describe as the most exciting challenge of my career.
I am a person with great restlessness and curiosity to learn, discover what I do not know, as well as reinvent myself daily, someone who is curious about life and wants to know. I enjoy sharing knowledge.
This is my personal project but I also collaborate in other blogs, it is the case, the most important web on water currently exists in the US, if you are interested you can read my articles here.

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