Magnetic measurement

Introduction

Magnetic field measurement is an important measurement in the field of magnetism, and plays an important role in the application of magnetism. The size, shape and direction of the measured magnetic field can be obtained through the magnetic field measurement. In this article, well explain the principles, methods and applications of magnetic field measurement.

Principles

The principle of magnetic field measurement is to use the law that the magnet must have a mechanical effect when placed in a magnetic field or a moving magnetic field, or the principle of magnetic attraction and the principle of magnetic repulsion. According to this law, the most basic magnetic measurement instrument is a magnetometer. A magnetometer is a tool used to measure the gradient, direction, and magnitude of the earth’s magnetic field, or the magnetic field of any object that has magnetic properties. Generally speaking, there are two methods of magnetometer measurement: one is to measure the magnetic field directly, and the other is to measure the intensity and direction of the magnetic field by making use of magnetic properties.

Methods

1. Hall Probe. Hall Probe is a kind of magnetometer which is more and more popular in the recent years. It belongs to the direct type of magnetic field measurement. It is mainly composed of Hall effect sensor, power supply and amplifier circuit. Its measurement principle is based on the Hall effect and Faradays law of electromagnetic induction. In a magnetic field, the Hall effect will generate an electromotive force due to the external force. This electromotive force generates a current in the circuit, which is proportional to the intensity of the magnetic field. By measuring the current generated by Hall effect, the intensity of the magnetic field can be obtained.

2. Fluxgate Magnetometer. Fluxgate Magnetometer is also a direct type of magnetic field measurement. It is composed of a core, a coil and a signal processing circuit. Put the core inside the coil. When a single winding of the coil is connected to an AC power supply, due to the magnetostriction of the material, the core changes its length periodically, followed by the coils inductance changing periodically. The changing inductance will induce a current in the secondary winding of the coil. By processing the induced current, the size and direction of the measured magnetic field can be obtained.

Applications

1. Magnetic field measurement is widely used in many industrial fields, magnetic field measurement of strong field is generally used in ordnance, aerospace and other research fields.

2. Magnetic field measurement is also used in remote sensing. For example, electromagnetic sounding uses magnetic field measurement to investigate the internal structure of the human body, and can also be used for geological prospecting.

3. Magnetic field measurement plays an important role in navigation, inertial navigation system, magnetic guidance and so on.

Conclusion

In conclusion, magnetic field measurement is an important measurement in the field of magnetism. The size, shape and direction of the measured magnetic field can be obtained through the magnetic field measurement. The principles, methods and applications of magnetic field measurement have been introduced in this article. Magnetic field measurement is widely used in industrial, remote sensing, navigation applications, and so on.

Magnetometry is the measurement of the strength and direction of magnetic fields. It is used in many fields such as medical diagnostics, engineering, and geography. Special instruments called magnetometers are used to measure magnetism.

In medical diagnostics, magnetometry is used to image organs such as the heart and brain. This imaging technology is called magnetic resonance imaging (MRI). This is done by measuring the orientation of protons within the body’s cells. The information from the proton orientation is presented as an image which can help diagnose certain medical conditions.

In engineering, magnetometry is used in designing machines such as electric motors and generators. Magnetometers can be used to measure the strength of magnets used in these machines. This information can be used to calculate how much torque the motor or generator produces.

In geography, magnetometry can be used to measure the strength and direction of the Earth’s magnetic field. This type of measurement is called geomagnetic surveys. Geomagnetic surveys can be used to map sites of archaeological and geological importance.

Magnetometry is an important tool in many different fields. It can be used to measure the strength and direction of magnetic fields, helping to diagnose medical conditions, design machines, and map areas of geological and archaeological importance. In this way, magnetometry helps us better understand the world around us.