UNI-T UT521 / UT522 Digital Ground Resistance Tester

UNI-T UT521 / UT522 Digital Ground Resistance Tester The UNI-T UT521 and UT522 are portable digital ground resistance testers designed for measuring earth resistance and AC earth voltage in electrical power systems, grounding systems, lightning protection installations, and other electrical equipment. Supporting both simple 2-wire and precise 3-wire testing, the UT520 Series provides a practical solution for electricians, field technicians, maintenance professionals, and electrical testing applications. The UT521 offers ground resistance measurement ranges up to 2,000Ω, while the UT522 extends the measurement range up to 4,000Ω. Both models feature data hold, data storage, LCD backlight, low battery indication, over-range indication, and double insulation protection. Key Features 2-Wire & 3-Wire Testing: Supports simple 2-wire and precise 3-wire earth resistance measurement. Ground Resistance Measurement: Designed for testing grounding and earthing systems. AC Earth Voltage Measurement: Measures AC earth voltage up to 200V on the UT521 and 400V on the UT522. Data Storage: Stores up to 20 measurement readings for convenient field testing and reference. Data Hold: Freezes the displayed measurement for easier reading and recording. LCD Backlight: Improves display visibility when working in low-light environments. Manual Range Selection: Allows users to select the appropriate measurement range. Low Battery Indication: Alerts the user when the batteries need to be replaced. Over-Range Indication: Displays “OL” when the measured value exceeds the selected range. Poor Contact Indication: Provides an indication when the grounding connection is insufficient. Double Insulation Protection: Provides additional protection during electrical testing. Portable Design: Lightweight housing makes the tester suitable for field service and on-site electrical inspections. Certifications: CE and UKCA certified. UT521 vs. UT522 Specification UT521 UT522 Earth Resistance Range 0–20Ω / 0–200Ω / 0–2000Ω 0–40Ω / 0–400Ω / 0–4000Ω Earth Resistance Accuracy ±(2%+10) / ±(2%+3) ±(2%+20) / ±(2%+3) AC Earth Voltage 0–200V 0–400V Display Count 2000 4000 Data Storage 20 readings 20 readings 2-Wire Testing Yes Yes 3-Wire Testing Yes Yes LCD Backlight Yes Yes Data Hold Yes Yes Auto Power Off Approx. 10 minutes Approx. 10 minutes Specifications Frequency 50Hz / 60Hz Power Supply 6 × 1.5V LR6 Batteries Display Size 70.6 × 34 mm Product Size 160 × 100 × 70.5 mm Net Weight 560g Product Color Red and Grey Insulation Protection Double Insulation Low Battery Indication Yes Over-Range Indication “OL” Poor Contact Indication Yes Standard Accessories 6 × 1.5V LR6 Batteries Simple test leads with alligator clips Standard test leads with alligator clips Earth spike Carrying strap Carrying bag User manual Applications The UNI-T UT520 Series Digital Ground Resistance Testers are suitable for a wide range of electrical testing and maintenance applications, including: Electrical grounding system testing Earth resistance measurement Lightning protection system testing Power system maintenance Electrical equipment grounding inspections Grounding system installation and verification Field electrical testing and maintenance UT521 / UT522 Ground Resistance Tester With portable construction, 2-wire and 3-wire testing capabilities, data storage, LCD backlight, and multiple protection and indication functions, the UNI-T UT521 / UT522 provides a convenient solution for professional ground resistance and earth voltage testing in the field.