UT620T 10A Digital Low Resistance Ohmmeter

UNI-T UT620T DC Resistance Tester

High-Precision Measurement for Professional Resistance Testing

The UNI-T UT620T DC Resistance Tester is a professional-grade instrument designed for precise measurement of DC resistance in a wide range of industrial applications. Featuring an impressive 0.1μΩ resolution, 10A maximum test current, and advanced four-wire measurement method, it delivers exceptional accuracy for testing transformers, motors, circuit breakers, and cable resistance. The large 7-inch color LCD screen offers clear visibility of all readings, while the dual power supply system (built-in rechargeable lithium battery and AC power) ensures uninterrupted operation in both field and laboratory settings. With specialized features such as temperature conversion, wire length measurement, and comprehensive data management capabilities, the UT620T provides the reliability and precision needed by power system engineers, maintenance technicians, and electrical testing professionals.

Key Features

• High-Resolution Measurement: 0.1μΩ resolution for precise resistance readings from 100.0μΩ to 1.0000MΩ
• Multiple Test Current Levels: Selectable test currents from 40mA to 10A with 8-level stepping capability for different testing requirements
• Four-Wire Testing Method: Eliminates lead and contact resistance for highly accurate measurements
• 7-inch Color LCD Display: Large, high-resolution screen for clear visibility of all measurement data
• Dual Power Supply System: 14.8V/5000mAh rechargeable lithium battery and AC 110-240V/50Hz power support
• Temperature Conversion: Two preset conversion temperatures (75°C and 115°C) for diverse testing scenarios
• Wire Length Measurement: Calculates wire length based on resistance value from 0.0001m to 999.99km
• Comprehensive Data Storage: Save up to 9999 sets of test data automatically, cyclically, or manually
• Built-in Thermal Printer: Instantly print test results with date, time, temperature, and resistance values
• Advanced Safety Features: Audible discharge alerts, high voltage warnings, and automatic discharge protection

Professional-Grade Precision for Demanding Applications

The UNI-T UT620T delivers exceptional measurement accuracy with its high-resolution capabilities and precision-engineered four-wire testing method. With measurement resolution down to 0.1μΩ and accuracy of ±0.1%rdg ± 0.1%fs in constant-current mode, it offers laboratory-grade precision in a field-ready instrument. The four-wire measurement technique separates current electrodes from voltage electrodes, eliminating the influence of lead resistance and contact impedance for true measurement values.

The instrument's variable test current capability (40mA to 10A with 8 stepping levels) allows technicians to select the optimal testing parameters for different applications, from delicate electronic components to heavy-duty power equipment. This flexibility makes the UT620T an invaluable tool for comprehensive electrical system analysis and preventive maintenance programs.

Comprehensive Measurement Capabilities

The UT620T combines essential resistance measurement with specialized functions designed for industrial applications. Beyond standard resistance testing, it offers:

• Temperature-compensated resistance readings with dual preset reference temperatures
• Wire length calculation based on measured resistance and known parameters
• Self-test mode with accessory standard resistor to verify measurement accuracy
• Real-time ambient temperature monitoring with optional temperature probe
• Automatic or manual data saving with 9999-set storage capacity
• Test result documentation via built-in printer or data export functions
• Transformer internal resistance testing for units below 1000kVA

The comprehensive testing capabilities make the UT620T suitable for a wide range of applications in power generation, distribution, and industrial maintenance where precise resistance measurement is critical for system evaluation and troubleshooting.

Convenient Operation with Dual Power System

The UNI-T UT620T is engineered for maximum operational flexibility with its dual power supply system:

• Built-in 14.8V/5000mAh rechargeable lithium battery pack provides up to 20W measurement power for field testing
• AC power support (110-240V/50Hz) delivers up to 150W measurement power for extended laboratory testing
• Automatic power source detection and seamless switching between power sources
• Intelligent power management with battery level indication and controlled output based on remaining capacity
• Auto-shutdown function to conserve battery power when operating on battery mode

This versatile power system ensures the UT620T can operate reliably in various environments, from remote field locations to workshop settings, without interruption or measurement compromises.

Data Management and Communication

The UT620T offers comprehensive data management capabilities for professional documentation and analysis:

• Built-in thermal printer for immediate test result documentation
• Extensive data storage capacity for 9999 sets of measurement data
• Multiple data saving modes: automatic, cyclic, or manual
• Data export capabilities via USB flash drive
• Optional Bluetooth connectivity for wireless data transfer
• Real-time data analysis with PC software for trending and reporting

These data management features transform the UT620T from a simple measurement device into a complete testing and documentation system, enabling technicians to maintain comprehensive records, generate professional reports, and perform trending analysis for preventive maintenance programs.

Professional Applications

Power Generation and Distribution

Power engineers and maintenance technicians rely on the UT620T's precision and versatility for:

• Transformer winding resistance measurement
• Circuit breaker contact resistance testing
• Busbar and connection point resistance verification
• Grounding system resistance analysis
• Cable resistance measurement and length determination

Motor Maintenance and Testing

Motor maintenance specialists leverage the UT620T's high precision for:

• Motor winding resistance measurement
• Winding temperature calculation through resistance method
• Winding-to-winding balance evaluation
• Connection and terminal resistance verification
• Preventive maintenance testing and documentation

Cable and Wire Testing

Cable installation and maintenance technicians depend on the UT620T's specialized features for:

• Cable resistance measurement with high precision
• Cable length verification through resistance method
• Continuity testing across long cable runs
• Splice and termination point resistance verification
• Cable quality evaluation and comparison

Manufacturing Quality Control

Quality control engineers utilize the UT620T for:

• Incoming component verification and testing
• Production line quality assurance testing
• Finished product electrical parameter validation
• Statistical process control with data recording capabilities
• Non-conformance documentation and analysis

Technical Specifications

Additional Features

• Display Type: 7-inch LCD color screen with adjustable brightness (5 levels)
• Test Method: Four-wire testing (separate current and voltage electrodes)
• Power Supply: Rechargeable lithium battery 14.8V/5000mAh or AC 110-240V/50Hz
• Battery Output: Maximum measurement power of 20W in battery mode
• AC Power Output: Maximum measurement power of 150W in AC mode
• Temperature Conversion: Preset 75°C and 115°C reference temperatures
• Data Storage: 9999 sets of test results with automatic, cyclic, or manual saving
• Automatic Discharge: Yes, with audible alert during discharge process
• High Voltage Warning: Yes, with hazard warning symbol for reverse voltage detection
• Auto-shutdown: Approximately 10 minutes of inactivity when on battery power
• Communication: Data transfer via USB flash drive, optional Bluetooth functionality
• Printer: Built-in thermal printer (57mm width paper) for test result documentation
• Product Dimensions: Approximately 386mm (L) x 318mm (W) x 159mm (H)
• Weight: 7.1kg (without accessories)

Package Contents

• UNI-T UT620T DC Resistance Tester
• Kelvin Test Leads (4-wire)
• Power Cord
• Thermal Printer Paper
• USB Drive (with software)
• User Manual
• Certificate of Calibration
• Carrying Case

Product Comparison

Frequently Asked Questions

Why is the four-wire testing method superior for resistance measurements?

The four-wire (Kelvin) testing method used by the UT620T eliminates measurement errors caused by test lead resistance and contact resistance, which can significantly impact readings, particularly at low resistance values. By separating the current-carrying circuit from the voltage-sensing circuit, the four-wire method ensures that only the resistance of the device under test is measured. This approach is essential for accurate measurements below 1 ohm, where even small lead resistances can introduce substantial errors. For applications such as transformer winding testing, motor resistance measurement, and cable resistance verification, this technique delivers the precision required for proper equipment assessment and troubleshooting.

What advantages does the variable test current provide?

The UT620T's selectable test current capability (40mA to 10A) provides significant advantages for different testing scenarios. Higher test currents (5A-10A) improve signal-to-noise ratio and measurement accuracy for very low resistance values, such as transformer windings and busbar connections. Lower test currents (40mA-1A) are ideal for testing sensitive components or devices that could be affected by higher currents. This flexibility allows technicians to optimize testing parameters for specific applications, ensuring accurate measurements while protecting the equipment under test. The instrument's intelligent current selection in AUTO mode further simplifies operation by automatically choosing the appropriate current based on the resistance range being measured.

How does temperature conversion benefit resistance testing?

The UT620T's temperature conversion feature addresses the challenge of resistance variation with temperature, which is particularly important for copper windings in transformers and motors. By offering preset conversion temperatures of 75°C and 115°C (standard reference temperatures in electrical engineering), the instrument allows technicians to normalize resistance readings to standard conditions for proper comparison. This capability is essential for equipment acceptance testing, manufacturer specification verification, and trend analysis in preventive maintenance programs. The ability to measure actual ambient temperature with an optional probe further enhances the accuracy of these temperature-compensated calculations.

What makes the dual power supply system beneficial for field technicians?

The UT620T's dual power supply system combines the convenience of battery operation with the sustained power of AC operation, addressing the diverse needs of field technicians. The built-in 14.8V/5000mAh lithium battery enables testing in remote locations, outdoor installations, and areas without reliable power access. When working in laboratory or workshop environments, the AC power capability provides extended operation for comprehensive testing programs without battery life concerns. The seamless switching between power sources and intelligent output management based on remaining battery capacity ensures testing continuity and instrument protection. This flexibility eliminates the compromises typically associated with single-power instruments, making the UT620T equally effective in all working environments.

How does the data management system enhance testing productivity?

The UT620T's comprehensive data management system significantly enhances testing productivity through multiple features. The built-in thermal printer provides immediate documentation of test results, eliminating manual recording errors and saving time. The extensive 9999-set data storage capacity allows complete testing sequences to be performed without interruption for data recording. Multiple data saving modes (automatic, cyclic, or manual) adapt to different testing workflows. Data export capabilities via USB and optional Bluetooth connectivity enable seamless integration with asset management systems and testing databases. These features combine to streamline the testing process, improve documentation quality, and facilitate more sophisticated analysis of electrical system performance over time.

Support and Warranty

UNI-T stands behind the UT620T with comprehensive technical support and a 1-year standard warranty. Our dedicated support team is available to assist with application questions, measurement techniques, and warranty service.

Professional-Grade DC Resistance Testing

The UNI-T UT620T DC Resistance Tester delivers exceptional precision, operational flexibility, and advanced features for professional electrical testing applications. With its 0.1μΩ resolution, four-wire measurement method, and comprehensive data management capabilities, it provides the reliability and accuracy needed by power system engineers, maintenance technicians, and quality control professionals working with transformers, motors, cables, and other critical electrical equipment.

Order Your UNI-T UT620T Today and Experience Professional-Grade Resistance Measurement Capabilities