Product Category
Resistivity & IP Systems
Electrical resistivity tomography (ERT) and induced polarization (IP) systems from AGI (Advanced Geosciences), IRIS Instruments, and Zonge International, for groundwater, contamination, geotechnical, and mineral exploration survey. Available New, Refurbished, Absolute Certified, or Surplus.
What is a Resistivity/IP System?
A resistivity system injects a known electrical current into the ground through a pair of electrodes and measures the resulting voltage at other electrode pairs, from which apparent electrical resistivity (Ω·m) is calculated. Because resistivity varies strongly with lithology, porosity, water saturation, and pore-fluid salinity, a resistivity survey — typically acquired as a 2D or 3D electrical resistivity tomography (ERT) grid using a multi-electrode cable array — builds a cross-sectional or volumetric image of subsurface electrical structure that can be inverted into a geological or hydrogeological model.
Induced Polarization (IP)
Many resistivity systems also measure induced polarization — the tendency of certain subsurface materials (notably disseminated sulfide minerals, clays, and some contaminants) to store and slowly release a small amount of injected charge, observed either as a decaying voltage after current shut-off (time-domain IP, or chargeability) or as a phase shift/resistivity change with frequency (frequency-domain/spectral IP). IP is a primary exploration tool for disseminated sulfide ore deposits (porphyry copper, and similar systems) that produce only a weak resistivity contrast but a strong chargeability response.
Electrode Arrays
- Wenner array: Equally spaced electrodes; good vertical resolution and signal strength, widely used for simple 1D/2D depth soundings.
- Schlumberger array: Closely spaced potential electrodes between widely spaced current electrodes; efficient for vertical electrical sounding (VES).
- Dipole-dipole array: Separated current and potential electrode pairs; good lateral resolution and standard for IP surveys and mineral exploration.
- Pole-pole / pole-dipole: One or more electrodes placed at effective infinity; larger depth of investigation for a given cable length, used for deeper or 3D surveys.
System Scale
Systems range from compact single-channel meters for quick VES soundings to automated multi-channel, multi-electrode systems (10 to 100+ takeouts on a resistivity cable) capable of acquiring full 2D/3D ERT datasets with minimal manual electrode switching, controlled via onboard sequencing software.
Resistivity & IP Brands We Supply
| Brand | Origin / Parent | Known For | Typical Application |
|---|---|---|---|
| AGI (Advanced Geosciences Inc.) | Independent (USA) | Multi-channel automated resistivity/IP systems (SuperSting-type) with built-in inversion software | Groundwater, geotechnical, ERT |
| IRIS Instruments | Independent (France) | Resistivity meters and multi-electrode systems (Syscal-type) for exploration and environmental survey | Mineral exploration, environmental |
| Zonge International | Independent (USA) | Time- and frequency-domain IP/resistivity transmitters and receivers for deep exploration | Mineral & geothermal exploration |
Condition Tiers for Resistivity/IP Equipment
Factory New
Transmitter, receiver, and cable set direct from the manufacturer, current firmware and sequencing software, full OEM warranty.
Refurbished
Cable takeouts, electrode connections, and switching electronics inspected; injection/measurement channels function-tested before dispatch.
Absolute Certified
Every channel verified for injection current accuracy, measurement noise floor, and (where applicable) chargeability decay response against a reference load; calibration certificate issued at handover.
Surplus
Decommissioned or excess survey-company transmitters, receivers, and cables, sold functional and as-is.
Frequently Asked Questions
Which electrode array should I use for my survey?
It depends on your target: Wenner and Schlumberger arrays are efficient for simple vertical soundings and good signal strength; dipole-dipole is the standard choice for IP surveys and lateral resolution of discrete targets like ore bodies; pole-pole and pole-dipole configurations extend depth of investigation for a given cable length, at the cost of some added noise sensitivity. Tell us your target depth, expected resistivity contrast, and whether IP is required, and we can help you specify a system.
Do refurbished multi-electrode cables still switch electrodes reliably?
Cable takeout connectors and internal switching relays are the parts most subject to field wear. Our Refurbished tier includes inspection and function-testing of every channel; our Absolute Certified tier goes further with full injection-current and noise-floor verification per channel against a reference load, so you know exactly which channels (if any) are degraded before you buy.
Can I add Surplus cable sections to a New or Refurbished resistivity system?
Usually yes, provided the cable connector type and channel-addressing protocol match your control unit — most manufacturers use proprietary takeout spacing and connector standards, so mixing brands is not generally possible, but adding same-brand Surplus cable sections to extend spread length is a common and cost-effective way to increase survey coverage.