SONEL_EARTH RESISTANCE & SOIL RESISTIVITY TESTER

Introduction:

The Sonel MRU Series Earth Resistance and Soil Resistivity Meters are advanced instruments designed for accurate earth resistance, soil resistivity, tower footing impedance and leakage current measurements using a wide range of testing methods. Designed for the most demanding working conditions, the Sonel MRU series generates a measuring current exceeding 200 mA, enabling reliable and effective testing of grounding systems at critical electrical installations such as transformer substations and power stations. The instruments are also suitable for electrically noisy environments and can measure interference voltage to help ensure dependable test results. 

The meters feature a compact, robust and user-friendly design, with different models available to suit various applications. An integrated connection correctness checking function guides the user through the correct test setup, reducing the possibility of connection errors and improving measurement reliability. An advanced 3-pole + Clamp (ART) method allows individual earth electrode resistance to be measured without disconnecting the electrode from the grounding mesh. This eliminates the need to disconnect control or grounding connections, which can be a time-consuming and difficult operation, particularly on outdoor installations exposed to harsh weather conditions where connection points may become corroded or tarnished. 

The Sonel MRU series is also suitable for tower footing impedance testing, as well as verification of grounding and lightning protection systems. Selected models can simulate conditions associated with lightning strikes by generating standardized impulse currents with defined pulse characteristics. Available impulse waveforms include 4/10 μs, 8/20 μs, and 10/350 μs, enabling testing for a range of lightning and surge-protection applications. 

For improved measurement accuracy, the instruments can also measure auxiliary electrode resistance and provide an error percentage, allowing the operator to assess the quality and reliability of the test conditions.

 With a rugged IP67-rated enclosure, the Sonel MRU series is designed to withstand demanding environmental conditions and is well suited for field applications in substations, power plants, transmission towers, industrial facilities, earthing systems and lightning protection installations. 

Overall, the Sonel MRU series combines advanced measurement technology, high-current testing capability, innovative clamp-based methods, impulse testing, robust construction and user-friendly operation, making it a highly versatile solution for professional earth resistance and soil resistivity testing.

Key Features:

• Measurement Facilities: 2-Pole, 3-Pole, 4-Pole, 3-Pole + Clamp, Stakeless, Tower Footing Impedance (TFZ), Leakage Current and Soil Resistivity measurement using the Wenner’s method.
• Measurement Voltage: 25 V and 50 V
• Measurement Current: 200 mA
• Interference Voltage: Up to 100 V
• Leakage Current Measurement Range: 0.1 mA to 300 A
• 3-Pole & 4-Wire Resistance Measurement Range: Up to 19.99 kΩ
• 3-Pole + Clamp Measurement Range: Up to 1,999 Ω
• Stakeless Measurement Range: Up to 149.9 Ω
• Impulse Method Measurement Range: Up to 300 Ω
• Soil Resistivity Measurement Range: Up to 999 kΩ·m
• Memory Capacity: 990 measurement results
• Data Transmission: USB and Bluetooth (BT)
• Standards of Compliance: ISO 9001, EN 61326-1, EN 61326-2-2, EN 61010 and IEC 61557

Available Models: 

MRU-10, MRU-12, MRU-21, MRU-30, MRU-30-Pro, Mru-120, MRU-120HD, MRU-200, MRU-200 GPS