What is a magnetic field sensor? Structure, classification and some common applications

Magnetic field sensing has become an indispensable technology in many practical applications, from installation on product lids to detecting broken drill bit sections on CNC machining machinery. But in order to better understand this device, we need to learn about the structure, principle of operation, classification and application of magnetic field sensors. Let’s discuss with RX Tradex to explore the magnetic field sensor in more detail in the article below!

1. What is a magnetic field sensor?

Magnetic field sensors, also known as Inductive Sensors, belong to the group of magnetic proximity sensors, used to detect changes in magnetic fields such as direction, strength and magnetic flux. At a fixed distance, they are capable of detecting magnetic carriers such as metals.

Currently, sensor devices are classified into two main groups: those used to calculate the total magnetic field and those used to calculate the vector components present in the magnetic field. For sensor products that calculate vector components, it is necessary to use techniques related to a mixture of electronics and physics.

2. Structure and outstanding features of magnetic sensors

2.1. Structure of magnetic field sensor

The magnetic field sensor is composed of the following main parts:

• Inductor: This part is used to conduct direct current. The inductor can be paired in series or parallel with the capacitor to form a resonant circuit.
• Inductors and signal processing: In this section, information from the inductor is processed to give a qualitative or quantitative parameter. This process helps meet research needs in the field of engineering science.
• Control output: Performs the task of monitoring and controlling the processes taking place in the sensor.

2.2. Outstanding features of magnetic field sensors

Magnetic field sensors are popular and used in today’s life thanks to the following outstanding advantages:

• The ability to operate in any environmental conditions, including the harshest ones.
• The extended service life, superior to many other types of sensor devices, allows users to use it for a long time without worrying about replacement.
• The structure is simple, easy to install and use even for non-technical people.
• Affordable cost of use, helping to save costs for users.

3. The principle of operation of the magnetic field sensor

The magnetic field sensor works on the principle of magnetic fields and electromagnetic phenomena, specifically as follows:

• When powered, current flows through the inductor in the sensor, creating a magnetic field at the probe. When a metal object appears in this area, it changes the sensor’s magnetic field. The sensor will immediately send an alarm signal to the controller to recognize the detection of an object.
• With sensors of large size and cross-section, the emitted magnetic field will be even stronger. This means that the ability to detect and detect objects in the area will be enhanced, increasing the efficiency of the sensor.

4. Types of magnetic sensors

Magnetic field sensors are classified into three main groups based on different magnetic ranges:

4.1. Low magnetic field sensor

This type of sensor is capable of detecting extremely low magnetic field values, which is often used in the detection of materials such as nuclear processions, SQUID (Superconducting Quantum Interference Device), or in fiber optic applications. They are widely applied in nuclear technology and the medical field.

4.2. Earth’s magnetic field sensor

This type of sensor uses the Earth’s natural magnetic field, which ranges from 1 microgauss to 10 gauss. Often used for orientation and positioning in applications such as in moving vehicles.

4.3. Magnet magnetic field sensor

This device is capable of sensing large magnetic field values, often exceeding 10 gauss. Often used in industries that use permanent magnets, devices in halls, GMR (Giant Magnetoresistance) sensors, or in industrial devices such as magnetic switches.

5. Application

Magnetic field sensors have many applications in today’s life, but the most common are in the fields of manufacturing, satellite technology and consumer electronics. Here are some typical applications of magnetic field sensors in practice:

• Induction cooktop: Magnetic field sensors are used to control and regulate the temperature on the induction cooktop, helping to ensure safety and efficiency in cooking.
• Fluorescent lamps: Magnetic field sensors are integrated into fluorescent lamps to adjust and maintain lamp brightness, improving lamp performance and service life.
• Generator: In generators, magnetic field sensors are used to control and regulate the output speed and voltage, ensuring stable operation and high performance.
• Medical applications: Magnetic field sensors are applied in modern medical devices such as cell transplants, magnetic resonance imaging (MRI) machines, and temperature regulating devices for cancer patients.
• Product detection and classification: In manufacturing plants, magnetic field sensors are used to detect and classify products based on their magnetic field properties, which enhances manufacturing processes and product quality.
• CNC machine: In CNC machining technology, magnetic field sensors are used to position and control the position of cutting and working tools, ensuring accuracy and performance during machining.

6. Summary

In fact, magnetic field sensors have a wide variety of applications in many fields such as medical, manufacturing, and CNC machining technology. The development and application of magnetic field sensors are playing an important role in improving performance and quality in various fields, especially in electronics industrial manufacturing. Hopefully, with the above information, you also have a better understanding of what a magnetic field sensor is, as well as the structure and principle of operation of a magnetic field sensor.

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