Breaking the Long-Term Drift Barrier: Hefei Moce Demonstrates Less Than 0.3 nT Drift Over 72 Hours

Long-term drift has long been one of the most challenging obstacles in atomic magnetometry.

While modern atomic magnetometers can achieve exceptional sensitivity, maintaining absolute accuracy and stability over extended periods remains difficult. Slow measurement drift over hours or days can significantly affect applications that require continuous, high-precision magnetic field monitoring, including geomagnetic navigation, geophysical surveys, earthquake-related magnetic research, and long-term observatory measurements.

Today, Hefei Moce Technology Co., Ltd. announces a major engineering breakthrough in addressing this challenge.

The Challenge of Long-Term Drift

Long-term drift is caused by the combined influence of multiple factors within an atomic magnetometer system, including:

• Temperature-induced changes in vapor cells, lasers, RF coils, and photodetectors
• Optical pumping power and frequency fluctuations
• RF excitation instability
• Electronic offset and gain drift
• Environmental magnetic disturbances
• Aging effects within the atomic sensor itself

Because these mechanisms interact simultaneously, suppressing long-term drift has remained a persistent challenge across the industry.

For many applications, sensitivity alone is not enough. Reliable long-term measurements require both high sensitivity and exceptional stability.

From Hours to Days of Stable Operation

To better understand the scale of the problem, the Moce engineering team conducted long-duration evaluations of commercially available atomic magnetometers.

In a representative test, a widely used atomic magnetometer exhibited approximately 30 nT of drift over a 10-hour period.

Although 30 nT may appear small compared to Earth's magnetic field of roughly 50,000 nT, such deviations can become significant when measuring weak magnetic anomalies or conducting long-term scientific observations.

Rather than treating this limitation as unavoidable, the Moce team launched a dedicated effort to reduce long-term drift through a combination of hardware optimization, system-level engineering, signal processing improvements, and algorithmic compensation.

The first stage of development reduced long-term drift to:

Less than 5 nT over 10 hours

Encouraged by these results, the team continued refining the system through months of additional testing and optimization.

The final outcome exceeded expectations:

Less than 0.3 nT drift over 72 hours (3 days).

Independent Long-Term Verification

To verify performance under real measurement conditions, a QTFM-Mozi 1.0 atomic magnetometer was operated continuously for more than 80 hours alongside a nearby GSM proton magnetometer.

Throughout the test period, the difference between the two instruments remained within 1 nT, demonstrating excellent agreement and confirming the exceptional long-term stability of the Moce system.

The results show that ultra-stable atomic magnetometer operation is achievable not only in laboratory demonstrations, but also in practical long-duration measurements.

Why It Matters

This achievement is not merely an improvement in specifications.

It addresses one of the key limitations that has historically restricted the deployment of atomic magnetometers in long-term field applications.

The benefits include:

• Reduced calibration requirements
• Improved confidence in long-duration measurements
• Lower operational costs
• Greater suitability for autonomous and unattended deployments
• Enhanced reliability for scientific and industrial users

Most importantly, it enables high-sensitivity atomic magnetometers to deliver the long-term stability required for real-world applications.

Looking Ahead

The reduction of long-term drift represents an important milestone in the engineering development of atomic magnetometers.

At Hefei Moce Technology Co., Ltd., we remain committed to advancing quantum sensing technologies and transforming laboratory performance into practical field-ready instruments.

From geomagnetic navigation and geophysical exploration to earthquake monitoring and emerging scientific applications, we will continue pushing the boundaries of precision magnetic measurement.

Making invisible magnetic fields measurable, stable, and useful for the real world.

Hefei Moce Technology Co., Ltd.

Quantum Sensing • Atomic Magnetometers • Precision Magnetic Measurement Solutions