Uni-T UT139B True RMS Digital Multimeter

The Uni-T UT139B is a professional-grade True RMS digital multimeter engineered for precise electrical measurements in various environments. This device combines robust construction with reliable performance, making it an essential tool for both industrial maintenance and domestic electrical troubleshooting. It features a clear display with a 31-segment analog bar graph, ensuring that technicians and hobbyists can monitor readings with high accuracy and efficiency.

Advantages

This multimeter stands out due to its True RMS capability, which ensures accurate measurements even with non-sinusoidal waveforms. The inclusion of the V.F.C. (Voltage Frequency Converter) function allows for stable readings in noisy electrical environments, such as near variable frequency drives. With its CAT III 600V safety rating, the device provides peace of mind during operation, while the NCV (Non-Contact Voltage) detection feature enables quick and safe identification of live wires without direct contact.

Suitable for

• General electrical troubleshooting and maintenance
• Testing voltage, current, and resistance in household appliances
• Diagnosing electronic circuits and components
• Field service and industrial equipment repair
• Educational purposes and hobbyist electronics projects

This device may not be suitable for high-voltage industrial applications exceeding the 600V CAT III rating. Additionally, users requiring specialized features like high-precision laboratory-grade data logging or extremely high-frequency signal analysis may find the capabilities of this general-purpose multimeter limited.

Key specifications

• Measurement range: DC/AC voltage up to 600V, DC/AC current up to 10A
• Resistance measurement: up to 40 MΩ
• Capacitance measurement: up to 99.99 mF
• Frequency range: 10 Hz to 10 MHz
• Safety rating: CAT III 600V
• Display: 4000-count with analog bar graph and backlight
• Power: 2x 1.5V AA batteries

To use the Uni-T UT139B, insert the provided batteries into the rear compartment. Connect the test leads to the appropriate input jacks based on the parameter you wish to measure. Select the desired function using the rotary dial, and use the range button to toggle between automatic and manual modes if necessary. The device will display the measured value on the LCD screen, and you can utilize the Data Hold or Max/Min buttons to capture specific readings during your testing process.

What to consider before purchase

• Verify that the measurement ranges meet your specific project requirements
• Ensure the CAT III 600V safety rating is sufficient for your intended work environment
• Confirm that the physical size and weight are suitable for your portability needs
• Check if the included accessories cover your immediate testing requirements

Always inspect your test leads for any signs of damage before use. Ensure the multimeter is set to the correct measurement mode before making contact with live circuits to prevent damage to the device or injury.