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Australian Made – Safearth designs and builds specialist test instruments for power system earthing
Safearth designs and builds specialist test instruments for power system earthing. Our instruments are developed by engineers who use them in the field, so every feature is shaped by real testing challenges and practical site requirements.
When we began performing crushed rock electrical resistivity testing for our customers, it was to relevant standards and following the prescribed methods. Quickly, we saw an opportunity to make the process safer, more repeatable, and easier to report. The standard method worked, but the practical setup and implementation left room for improvement.
Drawing on our experience in test instrument development, we adapted proven technology and engineered a dedicated solution for measuring the electrical resistivity of crushed rock in a test vessel. After resolving the unique challenges of this application, we developed an instrument that:
- is portable and battery powered;
- simplifies connections between meters, leads, and power supplies;
- reduces risk by removing the need for a 240 V supply near water;
- delivers accurate, repeatable test results; and
- automates much of the testing and reporting process.
The result is a practical, purpose-built instrument suited to both laboratory testing and onsite use.
We also refined the standard test vessel design, introducing changes that make the process less fiddly, more consistent, and easier to perform with confidence.
We would like to introduce you to the newest Safearth product, the RT2 Aggregate Resistivity Tester… or the RT2 for short.
The installation of crushed aggregate within substations and around HV assets acts to increase the impedance of touch and step voltage circuits, reducing the current that flows through an exposed person and reducing the risk of fibrillation for that person. It is incumbent on HV asset designers, constructors, and operators to ensure that any risk reduction measures are implemented using materials that meet design requirements. Verifying that the crushed aggregate used in and around HV assets meets design or standards designated resistivity requirements is vital in ensuring that risk outcomes meet expectations.
The RT2 is a portable test instrument designed to make aggregate resistivity testing fast, accurate, and repeatable under laboratory or field conditions. It guides the operator through a structured multi-stage test procedure and delivers resistivity results directly — no manual calculations required.
Full Test mode measures the resistivity of an aggregate sample across up to six defined conditioning stages, providing a complete resistivity profile of the material under dry, saturated, and drained conditions.
Quick Test mode delivers a single rapid resistivity measurement for spot-checking or screening purposes.
- Reliably test in-service assets.
- Measure aggregate resistivity in compliance with AS 1141.3.1:2021, PES-TR-107.
- Guided multi-stage test procedure with onscreen instructions.
- Direct resistivity readout in ohm-meter (Ω·m) or ohm-foot (Ω·ft), user selectable.
- Automatic current injection and measurement — no manual calculations.
- Tests dry, saturated, and drained conditions in a single session.
- Ω·m resistivity resolution.
- User-configurable container geometry for different sample sizes or use with a non-Safearth test vessel.
- IP67-rated carry case and durable field components.
- Greater than 20 full tests per battery charge.
- Inbuilt self-test function.
- Automatic power off after 1 hour of inactivity.
- Configurable injection frequency and voltage.
- Imperial and metric display units.
- Easy-to-use menu-driven user interface.
- Built-in test history log.
- 1-year warranty.
- 1-year calibration period.
- Durable case and components.
Want to know more about the RT2?
Register your interest below, and we’ll be in touch with more details and updates.
