Product · Electromagnetic (EM) Systems
Geonics EM31 (Original)
The original-generation EM31 terrain conductivity meter — the predecessor to today's EM31-MK2, sharing the same boom-mounted single-operator design and 3.7 m coil spacing.
Refurbished Absolute Certified Surplus
This model is no longer in production — it has been superseded by the current EM31-MK2. PartnerGeometrics sources it through the used and refurbished market — available as Refurbished, Absolute Certified, or Surplus only.
About the Geonics EM31 (Original)
The original EM31 established the boom-mounted, single-operator terrain conductivity meter format that Geonics still uses today: a fixed 3.7 m intercoil spacing measures apparent ground conductivity and an in-phase (susceptibility) component continuously as the operator walks a survey line, without needing ground contact or electrodes. The current EM31-MK2 refines the original design's electronics, data logging, and drift performance, but the underlying measurement principle and coil geometry are unchanged.
Original-generation EM31 units remain fully functional survey instruments and continue to circulate through the used-equipment market — a cost-effective route into conductivity survey work for buyers who don't require the MK2's newer logging electronics.
| Specification | Value |
|---|---|
| Intercoil spacing | 3.7 m (fixed boom) |
| Effective depth | ~6 m (vertical dipole) / ~3 m (horizontal dipole) |
| Measured quantities | Apparent conductivity (mS/m) + in-phase (susceptibility) component |
| Generation | Original, pre-MK2 |
| Operation | Single operator, continuous walking survey |
| Output | Analog meter, with optional external data logger |
Available as Refurbished, Absolute Certified, or Surplus. See our condition tier guide for details on what each tier includes.