Zero Gauss Chambers & GA4 Hybrid Magnetic Shield System
Advanced benchtop magnetic shielding for quantum sensing, sensor development, calibration and precision measurement.
The GA4 Hybrid Magnetic Shield System combines four layers of passive MuMetal® shielding with nine internal active coils, integrated degaussing and software-controlled field adjustment. It provides both an ultra-low magnetic environment and the ability to generate controlled uniform fields and magnetic-field gradients.
For applications that require passive attenuation without active field control, Magnetic Shields USA also supplies a comprehensive range of three-layer Zero Gauss Chambers and the portable ZG-Mini.
GA4 Key Features
- Four-layer passive MuMetal® shield for high attenuation of static and low-frequency magnetic fields
- Nine internal active coils for field nulling and controlled field generation
- Three uniform field coils controlling Bx, By and Bz
- Five first-order gradient coils for spatial field control
- One second-order gradient coil for more advanced field correction
- Integrated degaussing system to reduce remanent magnetization
- Software-controlled operation through a nine-channel coil driver and data-acquisition system
- Low magnetic noise for sensitive quantum and magnetic-sensor applications
- Removable end caps providing access from either end
- Internal breadboard and access ports for mounting sensors, optics and experimental equipment
The standard system includes the GA4 shield, nine-channel coil driver, data-acquisition hardware, low-noise power supply, degaussing equipment, control software, cables and connectors. A magnetometer is not included.
GA4 Specifications
| Specification | Inches | Metric / detail |
|---|---|---|
| Internal diameter | 7.87 in | 200 mm |
| Internal length | 11.81 in | 300 mm |
| External diameter | 11.93 in | 303 mm |
| External length | 18.98 in | 482 mm |
| Passive shielding layers | 4 | 4 |
| Uniform field coils | 3 | Bx, By and Bz |
| First-order gradient coils | 5 | — |
| Second-order gradient coils | 1 | — |
| Axial access aperture | 1.93 in | 49 mm |
| Total mass – shield assembly | 63.7 lb | 28.9 kg |
Published GA4 Performance
The GA4 was developed and characterized through collaborative research involving Magnetic Shields Ltd and the University of Nottingham. The results were published in IEEE Transactions on Instrumentation and Measurement.
Published testing demonstrated:
- Passive axial shielding factor of approximately 1,000,000 at 0.2 Hz
- Shield-induced magnetic noise below 15 fT/√Hz
- Active nulling reduced the total static field from 1.68 nT to 0.23 nT
- Uniform fields deviating from the target field by no more than 0.5% over the characterized region
- First- and second-order gradients deviating from their target profiles by no more than 4%
- Active reduction of uniform fields and gradients by factors of approximately 19.5 and 19.8, respectively
Performance figures are based on the published test configuration. Achievable results depend on the external magnetic environment, experimental arrangement, degaussing, magnetometer performance and system optimization.
Published paper: Benchtop Magnetic Shielding for Benchmarking Atomic Magnetometers
Passive Shielding, Active Control and Degaussing
Passive MuMetal® Shielding
Four nested MuMetal® cylinders redirect external static and low-frequency magnetic flux around the internal working volume. The layer geometry and spacing have been optimized to provide high shielding performance while limiting thermally generated Johnson noise.
Active Field Control
The nine internal coils allow the user to generate controlled uniform magnetic fields and field gradients within the shielded volume. They may be used to null residual fields, compensate for gradients or generate defined magnetic conditions for sensor development, calibration and experimental research.
Integrated Degaussing
MuMetal® can retain a small amount of magnetization after exposure to external fields or magnetic objects. Degaussing applies a controlled alternating magnetic field that gradually reduces this remanent magnetization. Regular degaussing helps achieve lower residual fields and improves repeatability.
Common GA4 Applications
- Quantum magnetometer development: Testing and characterization of OPM, atomic-vapor and other quantum magnetic sensors
- Sensor calibration and benchmarking: Creating controlled magnetic fields and gradients for evaluating sensor response
- Quantum sensing research: Low-field environments for emerging quantum devices and experimental platforms
- Precision magnetometry: Measurement of weak magnetic signals with reduced external interference
- Biomedical sensor development: Development and testing of sensors used in MEG, MCG and other biomagnetic measurements
- Navigation and aerospace sensing: Evaluation of high-sensitivity magnetometers and magnetic navigation technologies
- Fundamental physics: Controlled low-field experiments involving atomic, optical and condensed-matter systems
- Component characterization: Testing magnetic sensitivity, offsets, drift and field-dependent behavior
GA4 or Passive Zero Gauss Chamber?
| Requirement | GA4 Hybrid System | Passive Zero Gauss Chamber | ZG-Mini |
|---|---|---|---|
|
Passive magnetic shielding |
Yes – four layers |
Yes – three layers |
Yes |
|
Active field nulling |
Yes |
No |
No |
| Controlled field generation | Yes | No | No |
| Uniform-field control | Three axes | No | No |
| Gradient control | Five first-order and one second-order gradient | No | No |
| Degaussing | Integrated | Optional | Optional |
| Range of sizes | One optimized benchtop platform | Six standard sizes plus custom designs | One portable size |
| Best suited to | Advanced research, sensor development and controlled-field testing | Passive attenuation, calibration, zeroing and research | Portable zeroing, offset checks and component storage |
MuMetal® Passive Zero Gauss Chambers
Manufactured in the USA by Magnetic Shield Corporation and supplied by Magnetic Shields USA, our passive Zero Gauss Chambers create a low and homogeneous magnetic-field environment for testing, calibration and scientific research.
Standard chambers use three nested layers of high-permeability MuMetal®, separated and aligned using non-magnetic spacers. Each chamber is fully fabricated and magnetically annealed to develop the material’s optimum shielding properties.
Standard three-layer chambers are designed to attenuate external static and low-frequency AC magnetic fields by up to 1,000,000 times. Residual fields below 5 nT and magnetic noise below 30 fT/√Hz may be achieved with appropriate degaussing.
Actual performance depends on chamber dimensions, orientation, ambient field conditions, degaussing and measurement configuration.
Passive Chamber Features
- Six standard chamber sizes
- Three layers of high-permeability MuMetal®
- Full welded construction
- Slip-fit covers
- Magnetic annealing after fabrication
- Non-magnetic spacers for layer isolation and alignment
- Non-magnetic support cradle included
- Optional degaussing coil
- Custom diameters, lengths and configurations available
- Optional access ports, feedthroughs and additional shielding layers
- Operating-temperature range of approximately −40 °C; 100 °C; 80 °C; 60 °C; 0.5 gauss (50 µT)
Standard Zero Gauss Chamber Sizes
| Magnetic Shields USA reference | A Inner Diameter |
B Inner Depth |
C Outer Diameter |
D Overall Length |
Layers | Thickness Per Layer | E Lid Penetration Diameter |
|---|---|---|---|---|---|---|---|
| MSL-03 | 3.00 in / 76 mm | 9.00 in / 229 mm | 5.25 in / 133mm | 11.25 in / 286mm | 3 | 0.025 in / 0.64 mm | 0.875 in / 22mm |
| MSL-06 | 6.00 in / 152 mm | 15.00 in / 381 mm | 8.25 in / 210 mm | 17.25 in / 438 mm | 3 | 0.025 in / 0.64 mm | 0.875 in / 22mm |
| MSL-09 | 9.00 in / 229 mm | 27.00 in / 686 mm | 11.25 in / 286 mm | 29.25 in / 743 mm | 3 | 0.030 in / 0.76 mm | 0.875 in / 22mm |
| MSL-12 | 12.00 in / 305 mm | 36.00 in / 914 mm | 14.25 in / 362 mm | 38.25 in / 972 mm | 3 | 0.040 in / 1.02 mm | 0.875 in / 22mm |
| MSL-18 | 18.00 in / 457 mm | 54.00 in / 1,372 mm | 20.50 in / 521 mm | 56.50 in / 1.435 mm | 3 | 0.062 in / 1.57 mm | 0.875 in / 22mm |
| MSL-24 | 24.00 in / 610 mm | 72.00 in / 1,829 mm | 28.4 in / 721mm | 76.4 in / 1940mm | 3 | 0.062 in / 1.57 mm | 0.875 in / 22mm |
Custom Zero Gauss Chambers
Where a standard chamber does not provide the required working volume, attenuation or access, custom chambers can be engineered for the application.
Custom options include:
- Alternative internal diameters and lengths
- Additional passive shielding layers
- Custom layer thicknesses
- Access ports and instrument feedthroughs
- Removable or specialized end covers
- Integrated degaussing coils
- Custom support cradles
- Designs for alternative operating temperatures
- Testing and performance verification
ZG-Mini Portable Zero Gauss Chamber
The ZG-Mini is a compact, portable magnetic shield for laboratory, benchtop and field applications requiring a small, stable low-field volume.
Its lightweight non-magnetic housing allows the chamber to be used in any orientation, making it particularly suitable for sensor zeroing, offset checks and storage of magnetically sensitive components.
ZG-Mini Specifications
|
Specification |
|
|---|---|
| Working-volume diameter | 1.38 in / 35.1 mm |
| Working-volume length | 8.55 in / 217.2 mm |
| Axial attenuation after degaussing | 2,500:1 |
| Transverse attenuation after degaussing | 25,000:1 |
| Maximum shielding temperature | 100°C |
| Maximum housing temperature | 80°C |
| Maximum degaussing-coil temperature | 60°C |
Attenuation was measured at the center of the chamber using a MAG-13 fluxgate magnetometer under an ambient Earth field of approximately 0.5 gauss/50 µT, with the chamber openings facing east-west.
ZG-Mini Applications
- Zeroing magnetometers and gaussmeters
- Magnetic-sensor calibration
- Sensor offset measurement
- Fluxgate-probe checks
- Portable low-field experiments
- Storage of magnetically sensitive components
- Educational and laboratory demonstrations
Manufactured and Supported by Magnetic Shielding Specialists
The GA4 Hybrid Magnetic Shield System is manufactured by Magnetic Shields Ltd in the United Kingdom. Developed in collaboration with academic researchers, it combines optimized passive shielding, precision-manufactured flexible PCB coils and integrated degaussing in one benchtop platform.
The passive Zero Gauss Chamber range and ZG-Mini are manufactured in the United States by our partner, Magnetic Shield Corporation, a specialist manufacturer of MuMetal® shielding materials and fabricated magnetic shields.
Magnetic Shields USA provides North American sales, application support and a single point of contact across the complete range. Whether your requirement is passive attenuation, portable sensor zeroing or advanced active field control, we can help identify the most appropriate platform.
Frequently Asked Questions
What is a Zero Gauss Chamber?
A Zero Gauss Chamber is a passive magnetic enclosure designed to reduce external static and low-frequency magnetic fields within an internal working volume. Despite the name, it does not necessarily produce an absolute field of zero gauss. The achievable residual field depends on the chamber design, environment and degaussing process.
What is the difference between the GA4 and a passive Zero Gauss Chamber?
A passive chamber attenuates external fields using layers of high-permeability magnetic material. The GA4 combines four passive layers with nine internal coils, allowing the user to null residual fields, compensate for gradients and generate controlled magnetic-field profiles.
Can the GA4 generate magnetic fields as well as cancel them?
Yes. Its nine internal coils generate three uniform fields, five first-order gradients and one second-order gradient. These can be adjusted to cancel unwanted fields or create defined magnetic conditions for testing and research.
Does the GA4 automatically achieve a zero field?
The software-controlled coil system allows the required coil currents to be set and adjusted. A suitable magnetometer is needed to measure the internal field and determine the required nulling values. The magnetometer is not included with the GA4.
What performance has the GA4 demonstrated?
In published research, the active coil system reduced the measured static field from 1.68 nT to 0.23 nT over the characterized central region. The same research demonstrated passive shielding of approximately 1,000,000 at 0.2 Hz and shield-induced magnetic noise below 15 fT/√Hz.
What is the usable volume inside the GA4?
The internal chamber measures 200 mm in diameter × 300 mm long. The most suitable working region depends on the required field uniformity, gradient and performance target; the entire physical cavity should not automatically be treated as a uniformly characterized active volume.
Why is degaussing important?
MuMetal® may retain remanent magnetization after exposure to external fields, magnetic tools or nearby equipment. Degaussing progressively reduces this magnetization, helping to lower the residual internal field and improve stability and repeatability.
How often should a chamber be degaussed?
This depends on the required performance and operating environment. Degaussing is generally recommended after installation, relocation, exposure to strong magnetic fields or when measurement results indicate that the residual field has changed.
Can passive chambers be supplied with access ports?
Yes. Custom passive chambers can incorporate access ports, feedthroughs and other application-specific features. Every opening influences shielding performance, so its size and position should be considered during the design process.
Which chamber is best for sensor calibration?
The answer depends on what “calibration” requires. The ZG-Mini and standard passive chambers are suitable for sensor zeroing, offset checks and measurements within an attenuated field. The GA4 is more appropriate when controlled field generation, gradient control or advanced sensor characterization is required.
Are larger or custom Zero Gauss Chambers available?
Yes. Passive chambers can be manufactured with alternative diameters, lengths, layer counts, access arrangements and degaussing systems. Magnetic Shields USA can review the required working volume and performance before recommending a configuration.
What information is needed to specify a system?
Helpful information includes the sensor or experiment type, required working volume, ambient magnetic-field conditions, frequency range of interest, target residual field or shielding factor, required field uniformity, need for controlled field or gradient generation, and any required access ports, optical access or feedthroughs.
Talk to Us About Your Application
Tell us what you need to shield or measure, the required working volume and whether you need passive attenuation or controlled field generation. We will help identify the appropriate GA4, Zero Gauss Chamber or custom solution.