Products Description

HM3-100DC  Helmholtz Coil Magnetic Field Generator

1. Overview

A Helmholtz Coil consists of a pair of short coils with large radii (or side lengths for square coils) mounted on a common axis, separated by a distance equal to their radius. The magnetic field produced by a single coil is non-uniform. However, by superimposing the fields from the two coils, a relatively wide uniform field region is created near the geometric axis between them. Helmholtz coils are typically constructed in cylindrical or square geometries.

A one-dimensional Helmholtz coil system consists of a single Helmholtz coil pair. A two-dimensional system is composed of two mutually perpendicular Helmholtz coil pairs. A three-dimensional Helmholtz coil system consists of three Helmholtz coil pairs mounted orthogonally to each other, with their axes aligned along the X, Y, and Z directions, thus generating magnetic fields along those axes.

2. Applications

By utilizing the three-dimensional arrangement of the coils and adjusting the current ratio between the coil pairs, a magnetic field in any desired direction can be generated. Within the uniform region, the magnetic field strength of a Helmholtz coil is linearly proportional to the current and independent of position. The axial magnetic field strength can be calculated analytically based on the coil geometry, current, and number of turns. Therefore, Helmholtz coils are ideal magnetic field generators for instrument calibration and can perfectly cancel the Earth's magnetic field effect. They are used with devices such as Hall effect sensors, magnetoresistive sensors, fluxgate magnetometers, and SQUIDs. Helmholtz coils are used not only for magnetic field generation but also for quality measurement of permanent magnetic materials, such as magnetic flux and magnetic moment measurements.

3. Main Technical Specifications

Central Magnetic Field: 0 – 120 Gs (DC/AC, Customizable)

Coil Inner Diameter/Aperture: 100 mm (Customizable)

Uniform Region Diameter: 25 – 50 mm (Specifiable)

Uniformity: 10% – 0.1%

Configuration: One-dimensional / Two-dimensional / Three-dimensional (Customizable)

Operating Current: 0 – 8 A

Operating Frequency: 20 Hz – 100 Hz

Coil Type: Helmholtz

Field Type: DC / AC (Determined by the configured power supply)