Uni-T UT139S True RMS Digital Multimeter

Product Overview

The Uni-T UT139S is a professional-grade True RMS digital multimeter engineered specifically for electricians, HVAC technicians, and maintenance specialists who require precision in the field. Built with a rugged, ergonomic design, this meter provides high-resolution readings and a high-contrast display that remains legible even in dimly lit environments. Whether you are performing routine maintenance or complex fault-finding, the UT139S is designed to deliver stable and reliable performance every time.

Equipped with a 6000-count display and an analog bar graph, the UT139S offers a visual representation of signal fluctuations that standard digital readouts often miss. Its comprehensive measurement suite includes AC/DC voltage and current, resistance, capacitance, frequency, and temperature, making it a versatile all-in-one diagnostic tool for any service bag.

Why It Matters

Accuracy and safety are non-negotiable when working with electrical systems. The UT139S features True RMS for accurate measurements on non-linear loads and a specialized LoZ (Low Impedance) mode to eliminate ghost voltages that can lead to false readings. Combined with a CAT III 600V safety rating, this multimeter ensures you can diagnose residential and commercial systems with absolute confidence and protection.

What✓s Included

• Uni-T UT139S Digital Multimeter
• High-Quality Test Lead Set
• K-Type Temperature Probe
• Protective Rubber Holster
• User Manual

Features & Benefits

• True RMS: Ensures accurate AC voltage and current readings, especially on circuits with variable frequency drives or electronic ballasts.
• LoZ ACV Mode: Low impedance input identifies and eliminates phantom or ghost voltages for more accurate troubleshooting.
• Non-Contact Voltage (NCV): Safely detect live wires without making direct contact with the conductor.
• 6000 Count Display: High-resolution screen with a built-in backlight and 31-segment analog bar graph for real-time tracking.
• MAX/MIN/REL Modes: Easily capture peak values or calculate differences between two measurement points.
• Input Protection: Fully protected to CAT III 600V standards, ensuring durability against unexpected surges.
• Temperature Measurement: Includes a thermocouple for testing HVAC air temperatures and surface contacts.

Applications

• HVAC system diagnostics and motor testing.
• Residential and commercial switchboard maintenance.
• Solar PV installation and electrical troubleshooting.
• General appliance repairs and circuit board analysis.
• Automotive electrical system health checks.

Tradie Pro Tip

When you're dealing with long cable runs or multi-core cables, you'll often see 'phantom' voltage on your meter. Always switch the UT139S to LoZ mode to verify if the line is truly live. It saves a lot of head-scratching and keeps you safe from assuming a dead wire is live, or vice versa.

Pair With

• Uni-T Clamp Meters
• Insulated Tool Sets
• HVAC Temperature Probes

Keep Your Space Clean

Upgrade your diagnostic capabilities today. The Uni-T UT139S provides the precision and safety features required for modern electrical environments. Order now from HVAC Shop and ensure your toolkit is ready for the next job.