Sonel MMR 620 DLRO Micro Ohmmeter

The Sonel MMR 620 DLRO Micro Ohmmeter is a professional-grade instrument designed for precise measurement of very low resistance values in electrical circuits. Ideal for testing busbars, circuit breakers, transformers, welding joints, and high-current connections, this micro ohmmeter delivers accurate results with high repeatability, making it an essential tool for electricians, maintenance teams, and industrial engineers.

Equipped with advanced 4-wire Kelvin measurement technology, the MMR 620 ensures that contact resistance, lead resistance, and environmental factors are minimized for precise readings. Its robust construction, intuitive interface, and portable design make it suitable for both laboratory and field use.

Key Features:

• Measures very low resistances from 0.1 µΩ to 200 mΩ with high accuracy

• 4-wire (Kelvin) measurement method for precise results

• Adjustable test current up to 60 A for different applications

• Clear digital display with backlight and data logging capabilities

• Rugged, portable design for field use

• Automatic polarity switching and noise suppression for accurate readings

• Compliant with international standards for low-resistance measurements

Whether used for preventive maintenance, commissioning, or troubleshooting, the Sonel MMR 620 DLRO Micro Ohmmeter provides fast, reliable, and precise low-resistance measurements, helping ensure the safety and performance of electrical systems.

Specifications

1. Electrical Measurement

• Resistance Measurement Range: 0.1 µΩ – 200 mΩ

• Measurement Current: 1 A – 60 A (adjustable)

• Measurement Accuracy: ±0.2 % of reading ±2 digits

• Measurement Method: 4-wire (Kelvin) technique

• Display Resolution: Up to 0.1 µΩ

2. Measurement Functions

• Low-resistance testing of busbars, transformers, cables, and welding joints

• Measurement of contact and connection resistance

• Automatic polarity switching

• Noise suppression for stable readings

• Hold and data logging functions (optional, via software)

• Test duration adjustable for heating effects

3. Display & Interface

• Large backlit digital display for easy reading

• Menu-driven interface with clear icons

• Indicators for overload, connection error, and test status

• USB / RS232 interface for data transfer to PC (optional)

4. Safety & Compliance

• Overcurrent and short-circuit protection

• Compliant with IEC 61557-4 for low-resistance measurements

• Insulated and rugged housing for safe field operation

• Suitable for CAT III environments

5. Physical & Environmental

• Dimensions: Approx. 280 × 160 × 100 mm

• Weight: ~3.5 kg

• Operating Temperature: -10°C to +50°C

• Storage Temperature: -20°C to +70°C

• Humidity: 0 – 95 % non-condensing

• Housing: Rugged, portable, impact-resistant case

6. Accessories (Typical)

• Test leads and Kelvin clamps

• Carrying case for portability

• User manual and calibration certificate

• Optional software for logging and analysis

• High-current cables for 60 A measurements