The model G-822A cesium airborne magnetometer provides unmatched versatility of performance, size, function, and cost effectiveness. The G-822A sensor uses a precise, proven design with carefully selected and tested components to ensure the very best specifications in sensitivity, noise, heading error and absolute accuracy.

The G-822A magnetometer outputs a Larmor frequency that corresponds to the strength of the local magnetic field. This Larmor frequency is counted by a user-supplied counter or a professional compensator such as the RMS Instruments AARC500 Automatic Digital Compensator.

The sensor and electronics package is weatherproof, temperature controlled, and delivers full performance under extreme operating conditions. With a proven record of stable and reliable operation over long periods, the G-822A is the industry standard for manned aircraft and large-unmanned aircraft surveys.


Features and benefits

  • Versatile Multi-Sensor Array Capability: This instrument can be used in fixed wing, helicopter or land applications to fit any surveyor’s needs.
  • Highest Sensitivity: Measure the smallest variations in the magnetic field.
  • Fast Sampling: Better coverage at faster speeds.
  • Very Low Heading Error: Get very clean, repeatable measurements without fear of instrument noise impacting the data.
  • Low AC Field Interference: Survey next to power lines when necessary.
  • Rugged and Reliable: Weatherproof. Survives three-foot drop onto hard surface.
  • Ultra-stable: No need to calibrate sensors.
  • Export Version Available: Use anywhere in the world without need for an export license (except embargoed countries). See specifications.

Technical Details

G-822A Magnetometer Specification List

G-822A Magnetometer

  • Operating Principle: Self-oscillating split-beam Cesium Vapor (non-radioactive)
  • Operating Range: 20,000 to 100,000 nT
  • Operating Zones: The earth’s field vector should be at an angle greater than 6° from the sensor’s equator and greater than 6° away from the sensor’s long axis. Automatic hemisphere switching.
  • Sensitivity: < 0.001 nT/√Hz rms. Typically 0.003 nT P-P at a 0.1 second sample rate 0.02 nT P-P for CM-201
  • Heading Error: ± 0.15 nT (over entire 360° polar and equatorial spin)
  • Absolute Accuracy: < 3 nT throughout range
  • Output: Cycle of Larmor frequency = 3.498572 Hz/nT, 2 V P-P coupled through the sensor power input

  • Mechanical

  • Sensor: 2.375” (60.32 mm) diameter, 5.75” (146 mm) long, 12 oz. (339 g) - any orientation in 7” (177.8 mm) diameter stinger
  • Sensor Electronics: 2.5” (63.5 mm) diameter, 11” (279.4 mm) long, 22 oz. (623 g)
  • Cables:
  • Sensor to electronics: Standard 162 in. (13 ft. 6 in. or 4.1 m). Other lengths available from 2.4ft. (0.75m) at 40 in. (1 m) increments with connector on electronics end. Note: Cable lengths are approximate due to cable dielectric variations
  • Sensor Electronics to Counter: Standard 10 m, up to 165 ft. (50 m) (Coax with signal superimposed on power, requires decoupler board or box.)
  • Operating Temperature: -30°F to +122°F (-35°C to +50°C)
  • Storage Temperature: -48°F to +158°F (-45°C to +70°C)
  • Altitude: Up to 30,000 ft. (9,000 m)
  • Weatherproof: O-Ring sealed for operation in rain or 100% humidity.
  • Power: 24 to 32 VDC, 1 amp at turn-on and 0.5 amp thereafter.

  • Accessories

  • Standard: Power/Larmor coaxial cable (electronics to counter), standard length 10m, maximum 50m, spare O rings, operation manual and carrying/storage case.
  • Optional:
  • Signal/Power Decoupler, board or multi-channel box: Separates the Larmor signal from the power (28 V) to enable connection to Customer supplied counter.
  • Internal Decoupler: P/N 27504 - up to two sensor installation
  • External Decoupler: P/N 27560 - three and four sensor installation
  • Internal CM-221 Counter: See G-823A Magnetometer specifications
  • Stinger, Wingtip, Bird: Contact Factory for complete system integration information.
G-822A Magnetometer Shipping Weights & DIMS

Shipping Weights & DIMS

Contents Dimensions (L x W x H) Weight
Case 1 - G-822A Magnetometer 20in x 20in x 21in
51cm x 51cm x 53cm


  • In-Accessible Terrain: Difficult or dangerous terrain is no longer a problem, making it perfect for surveying wetlands, heavily vegetated areas, extreme terrain, or protected lands.
  • Environmental: Find abandoned wells, pipes, and storage tanks quickly and with precise positioning.
  • Archaeology: Survey vast distances and leave potential archaeology sites undisturbed from the air.
  • Geology: Survey for regional variations in the magnetic field.
  • UXO Detection: Collect data at high speed with a fast sample rate, making detection and delineation of UXO quick and easy.