Helmholtz coil introduction

一. Function Introduction

        The Hermann von Helmholtz coil has large volume in the uniform area, wide use space and simple operation. It can achieve one-dimensional, two-dimensional, and three-dimensional combined magnetic fields, and can provide AC and DC magnetic fields. There is a good linear relationship between current and magnetic fields. Suitable for various research institutes, universities, and enterprises to conduct material magnetism or detection experiments, applied to various disciplines such as materials, electronics, biology, medical, aerospace, chemistry, applied physics, etc. Its main purpose is to generate standard magnetic fields; Offset and compensation of geomagnetic field, geomagnetic environment simulation, determination of magnetic shielding effect, electromagnetic interference simulation experiment, calibration of Hall probes and various magnetometer, research on biological magnetic field and research on magnetic properties of materials.

二. Working principle

        The Hermann von Helmholtz coil is composed of a pair of identical circular conductor coils. The central axis of these two circular coils with a radius of R is coaxial with the Z-axis. The spacing between two circular coils is h=R. The turns of two circular coils.The number is the same, and each conductor coil carries the same directional current I, with a good linear relationship between the current value and the magnetic field value.

三. Structure Introduction

1. Characteristics of one-dimensional coils: Wide magnetic field space, horizontal or vertical magnetic field direction, capable of achieving relatively high magnetic fields, with a maximum magnetic field of up to 1000Gs. It is applicable to the generation of standard magnetic field, the calibration of Hall probes and various magnetometer, the study of biological magnetic field and the study of magnetic properties of materials.

2. Characteristics of two-dimensional coils: The magnetic field space is wide, and the general magnetic field direction is in the X and Z axes. The two-dimensional magnetic field can reach 100Gs simultaneously. It is applicable to the generation of standard magnetic field, the calibration of Hall probes and various magnetometer, the study of biological magnetic field and the study of magnetic properties of materials.

3. Characteristics of three-dimensional coils: The magnetic field achieves X, Y, and Z axial magnetic fields, with generally lower magnetic fields per axis. It is especially suitable for generating standard magnetic field, earth magnetic field cancellation and compensation, geomagnetic environment simulation, determination of magnetic shielding effect, electromagnetic interference simulation experiment, calibration of Hall probes and various magnetometer, research on biological magnetic field and research on material magnetic properties.

4. Characteristics of square coils: The uniform area has a large volume and open space, and is generally used for testing larger samples. The side length can reach 1 meter to several meters, and can be designed as one-dimensional, two-dimensional, or three-dimensional coils. It is applicable to the generation of standard magnetic field, the cancellation and compensation of the earth's magnetic field, the simulation of geomagnetic environment, the determination of magnetic shielding effect, electromagnetic interference simulation experiments, the calibration of Hall probes and various magnetometer, the study of biological magnetic field and the study of magnetic properties of materials.

5. The special shaped coil is a deformation based on the standard Helmholtz coil, with the main purpose of achieving maximum uniformity in a limited space. Some coils are limited by building space, experimental conditions, shielding room volume, or power supply, making the design and application of shaped coils particularly important under these special conditions .

四. Coil uniform zone

The size of the uniform zone of a standard Helmholtz coil is related to the diameter of the coil, and the larger the diameter of the coil, the larger the range of the uniform zone; The closer to the center of the coil, the better the uniformity.