Helmholtz Coils
A Helmholtz coil is vital in scientific, industrial, and research settings, producing uniform magnetic fields with adjustable magnitude and direction in multi-axis models. Higher uniformity across larger volumes requires bigger coils. Budget constraints often determine the feasible size of the coil and the extent of the uniform field achievable.
Our Specialty
We specialize in supplying high-quality Helmholtz coils, ideal for creating uniform magnetic fields. Ranging from single-axis to triple-axis designs, our coils offer precise control over full magnetic field vectors, suitable for a wide array of applications in research institutions, laboratories, and various industries. Our products accommodate magnetic field requirements from 1mT up to 50mT, with advanced water cooling systems integrated for coils operating above 5mT to ensure stability and performance. With a sterling track record, we have built a reputation for excellence, delivering durable and reliable coils that meet stringent specifications, ensuring our customers achieve their desired outcomes with confidence.
Applications
- Effects on Chemical Substances
- Biological Material Studies
- Earth Magnetic Field Cancellation
- Active Magnetic Shielding
- Electronic Equipment Testing
- Materials Science Research
- Aerospace Component Testing
- Magnetic Resonance Imaging (MRI) Enhancement
- Educational Demonstrations
Options
- Single, dual, and triple axis configurations for precise vector control.
- Range from 1mT to 50mT to meet diverse application needs. Higher field available on request.
- Water cooling options for high-power coils above 5mT.
- Trusted by research institutions and industry for reliability and performance.
Example Coil
| Parameter | Value |
|---|---|
| Coil Type | Helmholtz |
| Axis Count | 3 |
| Mount | Horizontal |
| Coil | Inner | Middle | Outer |
|---|---|---|---|
| Magnetic Field | 30 mT | 10 mT | 10 mT |
| Power | 1,000 W | 1,900 W | 2,200 W |
| Current | 40 A | 40 A | 44 A |
| Voltage (DC) | 26.4 V | 48 V | 50 V |
| Inductance | 12.6 mH | 13 mH | 23 mH |
| Inner Diameter | 200 mm | 357 mm | 518 mm |
| Outer Diameter | 304 mm | 452 mm | 610 mm |
| Coil Separation | 8 to 10cm | ~R_av | ~R_av |
| Cooling | Water | Water | Water |
Field Uniformity
Field uniformity is the evenness of a magnetic field within a space, crucial for accurate magnetic measurements. Helmholtz coils excel by providing a uniform magnetic field critical for sensor calibration and scientific research. Their paired coil configuration precisely controls magnetic conditions, offering consistency and reliability unmatched by other magnetic field generators.
+/- 1% Uniformity
For a width +/- 1% uniformity region, a coil of approximately 2.5 to 3 times the average diameter is needed. For example if you need a +/- 1% uniformity sphere of diameter 100mm/4in, you’ll need a coil with average diameter approximately 250mm/10in to 300mm/12in.
+/- 5% Uniformity
For a width +/- 5% uniformity region, a coil of approximately 2 times the average diameter is needed. For example if you need a +/- 5% uniformity sphere of diameter 100mm/4in, you’ll need a coil with average diameter approximately 200mm/8in. Compared to the +/- 1% uniformity region the volume is visibly larger. This is a reason many customers choose to lower their field uniformity requirements where possible to get the most cost effective coil.
Single Axis Helmholtz Coil
Single Axis Helmholtz Coils are the simplest and lowest cost of our Helmholtz coil offerings, with just a single pair of coils. These are particularly suited where the magnetic field is just required along a single axis through the center of the coils. It should be noted although the magnitude of the magnetic flux density is uniform in the uniformity region, the field angle will vary throughout, but is directly aligned along the axis at the coil center. If required we can provide field plots as part of a quote or a magnet design service. Typically aircooled coils are available up to approx 3mT/30G. Beyond these fields watercooling is likely necessary. Contacts sales@woodruffeng.com for more information.
Dual Axis Helmholtz Coil
Dual Axis Helmholtz Coils are a good compromise between the more expensive Tri Axis coils, and the low cost Single Axis coils. They are very capable in terms of good access, and the ability to control the magnetic field direction in a plane. Customers often use these magnets to make rotating or controlled magnetic field vectors in a plane with the capability to control the magnetic field magnitude.
Tri Axis Helmholtz Coil
Tri Axis Helmholtz Coils offer the most control over the magnetic field direction and magnitude. They enable full vector control and are ideal for advanced studies and complete magnetic field generation and cancellation. They are the higher cost optional due to the increased capability of the coils. These are most often used where a full 3D magnetic field vector scan is needed, and eliminate the need to reposition the sample.
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