The G-858 MagMapper Magnetometer is a high-sensitivity, fast-sampling ‘walking’ cesium vapor magnetometer. Its console includes a graphical interface that’s easy to learn and makes survey design and data review simple and efficient. The G-858 provides various modes of operation to allow the user to custom design a survey grid for their particular needs, or skip the grid entirely and use GPS! G-858 data acquisition offers either continuous or discrete station recording. The high sampling rate of the instrument in continuous mode allows the operator to survey an area at a fast walking pace. A lightweight data acquisition package enables you to survey large areas without having to stop for rest. A wider search zone and measurement of the magnetic field gradient can be achieved by adding a second sensor. The G-858’s internal firmware has been streamlined to include those features important for UXO, archaeological, environmental, utility, and mineral exploration.

The G-858 MagMapper is an industry proven magnetometer that you know you can rely on, both in the field and also through our world-class support department.


Features and benefits

  • Single or Dual Sensor Modes Easily go from a single sensor survey to either a vertical or horizontal gradiometer survey.
  • Fast Sampling: Save money and time on large-scale surveys. Eliminate gaps in the data.
  • Low AC Field Interference: Survey next to power lines when necessary.
  • Easy-to-use Interface: Useable by inexperienced personnel.
  • Rugged and Reliable: Weatherproof. Survives three-foot drop onto hard surface.
  • Long Battery Life: Each battery pack allows for 6 hours of surveying with single sensor and 4 hours with gradiometer.

Technical Details



  • Environmental: Find abandoned wells, pipes, and storage tanks quickly.
  • Archaeology: Perform basic magnetic archeology surveys.
  • Geology: Survey for regional variations in the magnetic field for mining and oil and gas applications.
  • UXO Detection: Collect data at high speed with a fast sample rate, making detection and delineation of UXO quick and easy.