Product · Magnetometers
Geometrics G-858 MagMapper
A cesium-vapor walking magnetometer widely used for archaeological, UXO, and geological survey work, offering high sensitivity in a portable backpack-carried form factor.
New Refurbished Absolute Certified Surplus
About the Geometrics G-858 MagMapper
The G-858 MagMapper is Geometrics' long-running cesium-vapor total-field magnetometer, carried as a backpack unit with the sensor mounted on a pole ahead of the operator. It can be configured as a single total-field sensor or as a vertical gradiometer using two sensors, and logs position-tagged readings for post-survey mapping.
Its combination of high sample rate and cesium-level sensitivity has made it a standard choice for archaeological prospection, UXO screening, and near-surface geological mapping for decades, and used units remain in active service worldwide.
| Specification | Value |
|---|---|
| Sensor type | Cesium vapor (optically pumped) |
| Configuration | Single sensor or vertical gradiometer |
| Sensitivity | Sub-nanotesla (cesium-grade) |
| Sample rate | Up to 10 readings/second |
| Carry format | Backpack, pole-mounted sensor |
| Positioning | Optional integrated GPS |
Available across all four PartnerGeometrics condition tiers — New, Refurbished, Absolute Certified, and Surplus. See our condition tier guide for details on what each tier includes.