QTFM Gen-2

QTFM Gen-2 sensor head and control electronics

The QuSpin Total-Field Magnetometer (QTFM) is a compact, high-sensitivity hybrid scalar + three-axis vector atomic magnetometer for geophysical applications. It is extremely accurate, stable, and can resolve minute field changes. A compact, low-power package makes it ideal for use in a wide range of applications from magnetic observatories to small, mobile platforms such as UAVs.

Release Notes: link
(Archived Gen-1 webpage: link)

Technical Specifications (Preliminary)

Sensitivity: Scalar: <3 pT/√Hz; Vector: <0.1 nT/√Hz (optional add-on)
Data Rate: 1000 samples/sec (maximum)
Bandwidth: 500 Hz
Deadzone: Axial only, < +/- 7º cone about earth’s field (typical < 5º) (diagram)
Heading Error: <3 nT uncompensated
Dynamic Range: 1000 nT to 150,000 nT
Operating Temperature: -15 deg. C to 55 deg. C
Size: 17.7×19.8×35.8 mm (sensor head), 14.7×24.4×92.3 mm (ECU housing)
Weight: 12 grams for sensor head + 29 grams for electronics/ECU (ECU without housing is 6.5 g)
Power: +5 V input (using SCB) or 10-12 V input (sensor powered directly), 2.5 W total, 3.5 W during startup
Slew Rate Limit:  None
Outputs:  UART (RS232), USB 
Max Gradient Field: 300 nT/cm
Calibration: None
Type: Pulsed laser-pumped rubidium, free induction decay (link)


  • Optional add-on: Integrated, stable, low-noise three-axis vector outputs (synthetic1 )
  • Flat spectral response (no frequency-dependent response roll-off)
  • Built-in customizable digital filters (low-pass, high-pass, notch)
  • Multiple sensors can be precisely synchronized for gradiometry
  • Negligible dead zones
  • No slew rate limitations (can tolerate extremely magnetically noisy environments)
  • Built-in high-resolution frequency counter

1Vector outputs are synthetically derived (calculated) from scalar measurements by applying bias fields in interleaved measurement cycles (link)


Qty 1-3: $10,000
Qty 4-7: $8,500
Qty 8+: $8,000
Vector add-on: +$1,500
Please call for pricing for larger volumes or potential OEM applications.

User Guide
3D CAD files

  1. Standard Comms Board (included with QTFM; for USB connectivity and power regulation)
  2. Triaxial Vector Upgrade (optional add-on; converts QTFM from scalar to hybrid scalar + three-axis vector magnetometer)
  3. Advanced Comms board (optional add-on; for wireless Bluetooth connectivity, GPS integration, and saving data to an onboard SD card)
  4. Carbon Fiber Housing (optional add-on; compact and robust external packaging)
  5. Battery pack (coming soon)
  6. Ethernet-based cable extension (coming soon)

Technical Support


Export Restrictions

QTFM is export controlled by the US Department of Commerce (ECCN: 6A006.a.2). QTFM can be shipped to most European countries, Japan, Australia, and South Korea without a license. Some key countries such as China, India, Russia are excluded and a license from the DOC is required before QTFM can be shipped to these countries.  A license approval can take over 8-12 weeks and requires detailed information on the end-user and end-use application.

A low-performance variant of the QTFM sensor (QTFM-B) with sensitivity worse than 20 pT/√Hz (ECCN: 6A996.a) is now available which can be shipped to nearly all countries without a license. The only operational difference between QTFM and QTFM-B is sensitivity.