Ground resistance and soil resistivity meter with Calibration Certificate MRU-200-GPS WMPLMRU200GPS

Comprehensive Grounding Diagnostics in a Single Device

This device stands out from the competition by supporting all known methods for measuring ground resistance. As a result, installers and auditors do not need to purchase additional instruments for different measurement scenarios. Tests can be performed using classic technical methods (3-pole and 4-wire), as well as in situations where traditional probes are difficult to drive into the ground. In such cases, the two-clamp method proves useful, enabling measurements without the need for additional auxiliary electrodes driven into the soil.

For structures equipped with lightning protection systems, the impulse (surge) method is critical, as it simulates atmospheric discharge conditions. It allows measurement of grounding impedance in accordance with the requirements of standard PN-EN 62305, which is essential for diagnosing the effectiveness of lightning protection. The device generates a measurement current exceeding 200 mA, ensuring reliable results even under challenging conditions, such as at transformer substations or in facilities with high levels of interference.

Precision and Additional Measurement Functions

Measurement accuracy is a top priority – the meter performs measurements compliant with standard PN-EN 61557 starting from values as low as 0.100 Ω. This resolution enables precise detection of even minor changes in ground resistance. In addition to basic functions, the device supports:

• Measurement of soil resistivity (Wenner method), which is crucial when designing new grounding systems.
• Verification of continuity in protective and equipotential bonding connections.
• Measurement of leakage or fault currents using dedicated clamps.
• Analysis of voltage levels and frequencies of interfering signals in the network.

The built-in GPS receiver is a feature that significantly simplifies fieldwork documentation. Measurement results are automatically saved together with location coordinates, eliminating the risk of errors when preparing reports for large, extensive networks or numerous check points. These data are stored in the device's internal memory (up to 990 results), allowing for later analysis without the need for immediate connection to a computer.

Application and Ergonomics

The instrument has been designed for demanding working conditions, offering resistance to harsh environments (IP54 protection class). Its versatility makes it suitable for use in the power industry as well as during inspections of installations in residential or industrial buildings. The ability to calibrate clamps and automatically calculate soil resistivity in various units (Ωm or Ωft) accelerates the measurement process and reduces the risk of calculation errors on the user's side.

Key operational range parameters include the ability to measure ground resistance using the 3-pole and 4-wire methods in a range from 0.100 Ω to nearly 20 kΩ, as well as the two-clamp method up to 150 Ω. For lightning protection purposes, impulse impedance measurement is available up to 300 Ω. The device also supports soil resistivity measurements up to 999 kΩm and leakage currents up to 300 A. All these data are displayed on a digital indicator with a resolution reaching 0.001 Ω in the lowest ranges, ensuring a high level of detail in the final report. Thanks to this interface, reading results is fast and clear even in full sunlight. The device does not have a built-in printer nor direct connection capability to an external printer – data must be retrieved via the USB interface or read from internal memory when generating the final report. This solution optimizes the device's weight and increases its reliability in the field.