UNI-T UT-275 Clamp Earth Resistance Tester

Measure earth resistance from 0.01Ω to 1000Ω without disconnecting the grounding system—the UT-275's clamp jaw simply snaps around the conductor, delivering accurate readings in seconds. With a 32mm jaw opening and a 4-digit LCD, this tester is built for fast, safe, and reliable field measurements.

Overview

The UNI-T UT-275 is a professional clamp earth resistance tester designed for measuring grounding resistance and leakage current in electrical systems. It uses a non-contact clamp method, eliminating the need for auxiliary ground rods or disconnecting the earth electrode. This makes it ideal for testing grounding in power distribution, telecommunications, industrial plants, and lightning protection systems. The tester offers a wide resistance range with high accuracy, plus leakage current measurement up to 20A, all in a rugged, portable design.

What stands out

• Clamp jaw opening of 32mm accommodates a wide range of grounding conductors
• Measures earth resistance from 0.01Ω to 1000Ω with accuracy up to ±1% + 2 digits
• Simultaneously measures leakage current from 0.00mA to 20.0A
• Alarm function for resistance upper/lower limits and current upper limit
• Data storage for up to 99 sets of measurements
• Auto range, data hold, backlight, and low battery indication for ease of use
• Safety rated CAT III 300V for safe operation in electrical environments

Technical details

• Earth Resistance Range: 0.01Ω to 1000Ω
• Earth Resistance Accuracy: ±1% + 2 digits (0.01Ω-20Ω), ±2% + 2 digits (20Ω-100Ω), ±3% + 3 digits (100Ω-400Ω), ±6% + 5 digits (400Ω-600Ω), ±10% + 5 digits (600Ω-1000Ω)
• Leakage Current Range: 0.00mA to 20.0A
• Leakage Current Accuracy: ±2% + 5 digits (0.00mA-10.0A), ±3% + 5 digits (10.0A-20.0A)
• Jaw Opening: 32 mm
• Display: 4-digit LCD with backlight
• Data Storage: 99 sets
• Alarm Function: Resistance upper/lower limit, Current upper limit
• Auto Range: Yes
• Data Hold: Yes
• Backlight: Yes
• Low Battery Indication: Yes
• Overload Indication: Yes (OL)
• Power Supply: 4 x 1.5V AA batteries
• Safety Rating: CAT III 300V
• Operating Temperature: -10°C to 50°C
• Operating Humidity: 20% to 90% RH

Our verdict

The UNI-T UT-275 combines precision, safety, and convenience in a rugged tool that's essential for any electrician or maintenance professional. Its clamp design saves time and effort, while the wide measurement ranges and alarm functions ensure reliable grounding system verification.