The Importance of Soil Electrical Resistivity Testing in Australia

Table of Contents

• What Is Soil Electrical Resistivity?
• Why Soil Resistivity Testing Matters in Australia
• Australia’s Unique Soil Challenges
• Insights from Research
• Choosing a Soil Electrical Resistivity Testing Company
• Key Benefits of Soil Resistivity Testing
• Final Thoughts

Soil Electrical Resistivity Testing (SERT), one of the methods included under electrical geophysical techniques, has significant importance in Australia’s wide-ranging and multi-faceted soil environments, with respect to the integrity, durability and performance of infrastructure projects. If you are building pipelines, electrical substations, solar farms or conducting a geotechnical investigation, knowing how your soil conducts electricity is critical to reducing the risk of corrosion and enhancing design precision.

What Is Soil Electrical Resistivity?

Soil electrical resistivity measures how strongly the soil resists the flow of electrical current (in ohm-metres). It’s influenced by several factors, moisture content, salinity, temperature, density, and soil type.

• Low resistivity soils (often moist or saline) conduct electricity more easily and are more corrosive to buried metal structures.
• High resistivity soils (dry or sandy) conduct less electricity and are less prone to corrosion.

Understanding this simple principle helps engineers make informed decisions when designing earthing systems, grounding networks, and corrosion protection plans.

Why Soil Resistivity Testing Matters in Australia

Australia’s extreme climate and wide range of soil types make ground resistivity measurement critical for safe and cost-effective engineering.

1. Corrosion Control for Buried Infrastructure
   Underground pipelines, power cables, and foundations are constantly exposed to varying soil conditions. Low resistivity values can signal a high corrosion potential, requiring protective coatings or cathodic protection systems. Without testing, asset owners risk costly maintenance and premature failures.
2. Electrical Earthing and Grounding Design
   In electrical and telecommunication systems, accurate resistivity testing ensures proper grounding design. It affects how fault currents dissipate safely into the ground, directly impacting safety compliance and system reliability.
3. Geotechnical and Environmental Assessment
   Studies have shown strong correlations between resistivity and key soil characteristics like moisture, salinity, and unit weight. This allows engineers to model soil behaviour more accurately and enhance geotechnical investigations with electrical data.
4. Renewable Energy Projects
   For solar and wind farms, grounding performance depends heavily on soil resistivity. Testing ensures reliable earthing, prevents electrical faults, and improves performance in remote Australian locations.

Australia’s Unique Soil Challenges

• Coastal vs Inland Conditions: Coastal regions have saline, low-resistivity soils prone to corrosion; inland areas often feature dry, sandy soils with high resistivity.
• Seasonal Variation: Moisture fluctuations during wet and dry seasons significantly change soil conductivity.
• Expansive Soils: In many Australian regions, reactive clays alter resistivity as they expand and contract.

These factors make site-specific resistivity testing a necessity, not an option, for reliable soil corrosion testing and earthing design.

Insights from Research

Some recent studies have shown that low soil resistivity is a function of moisture content and compaction, or salinity of the soil (effectively discussing an exponential model between geotechnical characteristics and electrical resistivity). Several other novel mathematical techniques, including ANNs, have been demonstrated to achieve better prediction than traditional linear methods in the context of resistivity prediction.

These empirical models underscore the importance of using geotechnical data in combination with resistivity tests to gain a more realistic understanding of soil, reduce field testing costs, and support earth system and corrosion mitigation designs in Australia.

Choosing a Soil Electrical Resistivity Testing Company

Choosing the right company to conduct soil electrical resistivity testing helps one get accurate, site-specific results that inform safe and efficient design decisions. Experienced testers understand how local soil conditions, moisture, and salinity affect the resistivity values, ensuring that the data is properly analyzed for applications in earthing design, pipeline protection, and infrastructure reliability.

A trusted provider such as Tempsand Pty Ltd. It provides specialist services in electrical resistivity and soil thermal conductivity testing across Australia. The company’s expertise enables engineers, builders, and renewable energy developers to achieve reliable, compliant, and data-driven assessments of soil, thus minimizing long-term risks to the projects.

Key Benefits of Soil Resistivity Testing

• Ensures accurate earthing system design and regulatory compliance.
• Reduces corrosion-related maintenance on pipelines and cables.
• Supports better geotechnical and environmental assessments.
• Improves project safety, reliability, and cost-efficiency.

Final Thoughts

Soil electrical resistivity testing is an essential part of the toolkit for engineers, utility managers and renewable energy developers in Australia’s wide range of soil types and environments. It supports the protection of infrastructure, better design, and reduced long-term risk — while ensuring projects meet Australian safety standards.

Avoid making decisions based on guesses, opt instead for soil resistivity testing as part of the geotechnical site investigation.

For accurate soil electrical resistivity testing and reliable geotechnical insights, get in touch with Tempsand Pty Ltd today, or call 0429-674-334 for more information.