Product · Electromagnetic (EM) Systems
Geonics EM47
Transient (time-domain) electromagnetic system for deep ground conductivity sounding — a long-serving Geonics instrument for groundwater and deep exploration applications.
Refurbished Absolute Certified Surplus
This model is no longer in general new production. PartnerGeometrics sources it through the used and refurbished market — available as Refurbished, Absolute Certified, or Surplus only.
About the Geonics EM47
The EM47 is a transient electromagnetic (TEM) system: rather than transmitting a continuous frequency like the EM31/EM34/EM38 conductivity-meter family, it energizes a transmitter loop laid on the ground, then abruptly cuts the current and measures the decaying secondary eddy-current field induced in the subsurface over time using a separate receiver coil. Because the received signal is sampled across a range of time gates after transmitter shutoff, a single sounding yields conductivity information over a much greater depth range than a fixed-frequency conductivity meter — making TEM systems like the EM47 well suited to deep groundwater exploration, mapping conductive overburden thickness, and general reconnaissance where depths of tens to over a hundred metres are of interest.
The EM47 sits in the Geonics TEM lineage alongside the smaller EM37 and larger-loop EM57 systems, distinguished primarily by transmitter loop size and the corresponding investigation depth. It remains functionally capable equipment and continues to be traded and refurbished for exploration programmes that don't require the latest digital receiver electronics.
| Specification | Value |
|---|---|
| Method | Transient (time-domain) electromagnetic sounding |
| Transmitter | Portable ground loop, variable size |
| Investigation depth | Tens to 100+ m, depending on loop size & ground conditions |
| Measured quantity | Decaying secondary field vs. time, converted to apparent resistivity/conductivity |
| Typical crew | 2 operators (transmitter + receiver) |
| Applications | Groundwater exploration, overburden mapping, mineral exploration |
Available as Refurbished, Absolute Certified, or Surplus. See our condition tier guide for details on what each tier includes.