Helmholtz Coils

A Helmholtz coil is a device for producing a region of nearly uniform magnetic field, named after the German physicist Hermann von Helmholtz. It consists of two electromagnets on the same axis, carrying an equal electric current in the same direction. Besides creating magnetic fields, Helmholtz coils are also used in scientific apparatus to cancel external magnetic fields, such as the Earth's magnetic field.

Dexinmag series Helmholtz magnetizing coils use DC (direct) current source to produce an AC or DC static magnetic field; There is a good linear relationship between the current and magnetic field.

Three-dimensional equal-diameter coils are three-dimensional Helmholtz coils designed exclusively by our company. Its characteristics are: the three dimensions of the coil diameter is equal, the same number of turns, the same diameter; uniform area volume, small size, large internal space, the overall frame of non-magnetic metal-free, especially suitable for use in the shielding tube. 

High evenness coil is based on standard Helmholtz coil, the deformation of the standard coil and the combination of compensating coil compound can improve the homogeneous degree of the coil in the effective space, expanding the scope of the uniform area, suitable for high accuracy for a wide range of magnetic field.

No magnetic moment coil through several groups of coils to a certain geometric structure of the installation, and through each group of a certain number of coil turns and a certain current direction, so that the magnetic field rapidly decays coil, the coil moment of zero.

Characteristics: The uniformity area is big, and the space is open. Generally used in large sample tests, the side length can reach 1m to several meters, and it can be designed as a one-dimensional, two-dimensional, or three-dimensional coil. 

Square Helmholtz Coil
1 Axis Helmholtz Coil
2 Axis Helmholtz Coil
3 Axis Helmholtz Coil

AC Helmholtz Coil/Power Frequency Magnetic Field Coil


The power frequency magnetic field coil is designed for the power frequency magnetic field immunity test, and it complies with the GB/T 17626.8 standard. Power frequency magnetic field coils should produce a magnetic field strength corresponding to the selected test level and the specified uniformity. The magnetic field strength can be up to 2 kA/m, and the magnetic field strength can be customized. The frequency coil designed and manufactured by our company is made of non-metal non-magnetic material, and its cross-section and mechanical structure are stable, which is conducive to stabilizing the coil during the test.

The coils are sized to surround the EUT (in three mutually perpendicular orientations) Customizing different sizes of power frequency coils according to the size of the EUT can produce a uniform magnetic field throughout the bench or vertical equipment volume with a deviation of ±3 dB. For small devices such as (computer monitor watt-hour programmed transmitters, etc.), the standard size induction coils are squares with sides of 1 m or round with a diameter of 1 m. Standard square coils have a test area volume of 0.6m*0.6m*0.5m. When larger volume equipment needs to be tested, standard-size dual coils can be used with a test area volume of 0.6m*0.6m*1.0m.

In order to accommodate three vertical magnetic field tests, the coil can be rotated from 90 degrees to 360 degrees, and the sample table can be rotated 360 degrees. Special requirements for power frequency magnetic field coil can be customized.

Magnetic Flux Coil


Both the Teslameter and the fluxmeter can measure the residual magnetic induction of the magnet, but when measuring a small magnet, measuring with a Hall probe (Teslameter) must accurately remove the distance between the probe and the sample surface, otherwise, the measurement error is Great. The use of Helmholtz coils with flux meters effectively solves this problem. Helmholtz coils are used to produce a uniform magnetic field, and vice versa, they can also be used for open-circuit sample flux measurements. The magnet under test is removed from the center of the coil. The magnetic flux in the Helmholtz coil changes the induced voltage and is transmitted to the fluxmeter. The fluxmeter obtains the flux variation through data processing.


Model Coil diameter
Sample diameter
DXT-100 100 40 1.5
DXT-200 200 80 2.8
DXT-300 300 120 3.5
DXT-400 400 160 4.4
DXT-500 500 200 5.3
DXT-600 600 240 6.8
DXT-700 700 280 7.5
DXT-800 800   8.9
DXT-900 900   10.2
DXT-1000 1000   13.6

Gradient Magnetic Field Coils


Gradient magnetic field design and production also have many forms, using the magnetic pole gradient pole, can generate a magnetic field that is not symmetrical, and is usually used in the need of the sample unidirectional force test, such as force method magnetometer, magnetic powder sample Screening; can also be multi-electromagnet, so that the magnetic field produces a uniform radial gradient magnetic field, the magnetic field is zero in the radial section, the center is evenly increasing magnetic field around the area as a standard circle, such a wide range of magnets Used in accelerators to focus and adjust charged particle beams.

Gradient magnetic field coils are used in the design of gradient magnetic fields to achieve one-dimensional, two-dimensional, and three-dimensional gradient magnetic fields. The usual method is to make two coaxial coils connected in series, set the best coil spacing, get the best gradient linearity of the magnetic field axis direction, but also adjust the appropriate coil distance, and get different sizes of gradient magnetic field; There are also applications where gradients of the same magnetic field direction are required. This need can be achieved by combining magnetic fields.

Design and Installation of Large Magnetic Field Coils


Design, manufacture, and install of large magnetic coils, according to customer's specific application scenarios, according to the requirements of Helmholtz coil, electromagnet, solenoid, constant magnetic field permanent magnet, welcome to consult, tel 18030236818 (same wechat number), obtain detailed product specifications and quotation.

Dexinmag series helmhotz coils for sale:

Home > Magnetic Field Source > Helmholtz Coils Product Introduction

How Helmholtz Coils Work?


When two coils are passed current in the same direction, they generate a magnetic field. This magnetic field can be described by Maxwell's equations. Since the Helmholtz coil is symmetrical, the magnetic field it produces is uniform along its axis.
When the two coils are supplied with reverse current, the superposition weakens the magnetic field, so that a region where the magnetic field is zero appears.

Main application:

Generate a standard magnetic field;
Offset and compensation of the earth's magnetic field;
Geomagnetic environment simulation;
Judgment of magnetic shielding effect;
Electromagnetic interference simulation experiment;
Calibration of Hall probes and various magnetometers;
Research on biomagnetic fields;
The study of the magnetic properties of matter.