UNI-T UT521 Digital Earth Resistance Tester

UNI-T UT521 Digital Earth Resistance Tester in Sri Lanka

Manual-Range 3-Pole Earth Pit Tester for Ground Resistance Measurement

The UNI-T UT521 Digital Earth Resistance Tester is a robust, entry-level instrument designed for accurate measurement of earth electrode resistance and ground rod resistance using the standard 3-pole fall-of-potential method. It is an essential tool for electricians and electrical engineers in Sri Lanka who need to verify earthing system integrity at industrial sites, residential installations, and power distribution infrastructure.

Explore our complete range of Earth Resistance Testers — digital earth testers, ground resistance meters, and loop impedance instruments in Sri Lanka!

With manual range selection, clear digital LCD display, and a built-in interference voltage check, the UT521 ensures reliable earth resistance readings even in electrically noisy environments. Its compact, handheld form factor makes it ideal for field earth pit testing and periodic grounding system verification across multiple sites.

Technical Specifications

Earth Resistance Range: 0~200Ω / 0~2kΩ / 0~20kΩ (manual range)

Resolution: 0.01Ω (200Ω range)

Accuracy: ±(2%+5dgts) for 200Ω; ±(3%+5dgts) for 2kΩ/20kΩ

Test Method: 3-pole / 2-pole earth resistance measurement

Test Frequency: ~820Hz (built-in)

Interference Voltage: AC ≤30V detection

Auxiliary Electrode Resistance: ≤50kΩ (C), ≤50kΩ (P)

Display: 3½-digit LCD

Power: 6 × 1.5V AA batteries

Dimensions: Approx. 195 × 90 × 52mm

Key Features

Manual Range Selection: Choose between 200Ω, 2kΩ, and 20kΩ ranges to suit different earth electrode conditions

Interference Voltage Alarm: Detects AC interference up to 30V to warn of stray current that could distort readings

3-Pole and 2-Pole Testing: Supports both standard fall-of-potential and simplified 2-wire methods for flexible site testing

Compact Handheld Design: Lightweight body suits field service use with easy one-hand operation

Auxiliary Electrode Tolerance: High auxiliary resistance tolerance reduces errors from poor soil contact

Applications

Earth pit resistance testing at industrial facilities and substations

Ground rod resistance verification at residential and commercial buildings

Routine earthing system inspection for electrical compliance audits

Grounding continuity checks at telecom towers and lightning protection systems

Package Includes

1 × UNI-T UT521 Digital Earth Resistance Tester

3 × Test lead wires (C, P, E terminals)

2 × Earth spike auxiliary electrodes

6 × AA batteries (installed)

Carrying case

English user manual

If you require auto-ranging convenience for faster on-site earth testing, consider the UNI-T UT522 Digital Earth Resistance Meter with automatic range switching and enhanced display.

Downloads

📄 Download UNI-T UT521 Data Sheet
📄 Download UNI-T UT521 User Manual