Insulation Resistance Tester, 500–2500 V, up to 100 GΩ, PI/DAR, UT512 UNI-T

UNI-T UT512 Insulation Resistance Tester, 500–2500 V, up to 100 GΩ, PI/DAR

The UNI-T UT512 is a digital high-voltage insulation resistance tester designed for checking the condition of insulation in electrical equipment, cables, motors, generators, transformers and other electrical systems. It provides selectable test voltages of 500 V, 1000 V, 1500 V and 2500 V and measures insulation resistance up to 100 GΩ, depending on the selected test voltage. PI and DAR functions, timed testing, 18-group data storage and a USB interface provide useful tools for both spot measurements and more detailed insulation-condition analysis.

Key specifications: 500 / 1000 / 1500 / 2500 V • up to 100 GΩ • PI / DAR • 18-group memory • USB • CAT III 600 V

Key features

• Four insulation test voltages: 500 V, 1000 V, 1500 V and 2500 V – allow the test voltage to be selected according to the equipment being evaluated.
• Insulation resistance measurement up to 100 GΩ – suitable for checking cables, windings, transformers, generators and other equipment with high insulation resistance.
• PI (Polarization Index) and DAR (Dielectric Absorption Ratio) – provide time-based insulation assessment rather than only a single instantaneous resistance reading.
• Timed and continuous test modes – suitable for insulation tests requiring a defined measurement duration; timed tests can be set for up to 15 minutes.
• Comparison function – allows a resistance threshold to be selected for quicker pass/fail assessment.
• 18-group data memory – stores measurement results for later review.
• USB interface and manufacturer PC software – enable stored measurement data to be transferred to a computer for analysis.
• Automatic discharge and high-voltage indication – improve safety when working with circuits that can retain charge after an insulation test.
• 9999-count LCD, 30-segment analog bar graph and backlight – provide clear monitoring of measured values and their changes.

Applications

The UT512 is intended for insulation-condition testing during electrical maintenance, diagnostics and periodic inspection. UNI-T specifies the UT510 series for insulation-resistance measurements on equipment such as large transformers, generators and high-voltage motors.

It is suitable for electricians, maintenance technicians and engineers requiring an insulation resistance tester with test voltages up to 2.5 kV, PI/DAR functions and measurement data storage.

Compatibility and limitations

• Available insulation test voltages: 500 V, 1000 V, 1500 V and 2500 V.
• Maximum specified insulation-resistance range for the UT512: 100 GΩ.
• AC and DC voltage measurement is available up to 600 V.
• Data transfer to a computer is via USB and the manufacturer's PC software.
• The UT512 is primarily an insulation resistance tester and is not a full-function digital multimeter.
• 100 V and 250 V insulation-test settings are not provided on the UT512.
• The UT512 does not provide a 5000 V insulation-test setting.

Technical specifications

Parameter	Value
Model	UNI-T UT512
Instrument type	Digital insulation resistance tester
Insulation test voltages	500 V / 1000 V / 1500 V / 2500 V DC
Test-voltage tolerance	+20% / −0%
Insulation resistance at 500 V	0.5 MΩ–5.0 GΩ
Insulation resistance at 1000 V	2 MΩ–10.0 GΩ
Insulation resistance at 1500 V	5 MΩ–20.0 GΩ
Insulation resistance at 2500 V	10 MΩ–100 GΩ
Insulation-resistance accuracy, 100 kΩ–100 MΩ*	±(3% + 5 digits)
Insulation-resistance accuracy, 100 MΩ–10 GΩ*	±(5% + 5 digits)
Insulation-resistance accuracy, 10 GΩ–100 GΩ*	±(10% + 5 digits)
Short-circuit current	<1.8 mA
DC voltage measurement range	±30 to ±600 V
DC voltage resolution	1 V
DC voltage accuracy	±(2% + 5 digits)
AC voltage measurement range	30–600 V, 50/60 Hz
AC voltage resolution	1 V
AC voltage accuracy below 100 V	±(2% + 8 digits)
AC voltage accuracy at ≥100 V	±(2% + 5 digits)
Polarization Index (PI)	Yes
Dielectric Absorption Ratio (DAR)	Yes
Comparison function	Yes
Continuous measurement	Yes
Timed measurement	Up to 15 min
Data storage	18 groups
Auto ranging	Yes
Auto power off	Yes
Automatic discharge	Yes
High-voltage indication	Yes
Over-range indication	Yes
Low-battery indication	Yes
USB interface	Yes
Display	9999-count LCD
Analog indication	30-segment bar graph
Backlight	Yes
Display size	123 × 58 mm
Safety category	CAT III 600 V
Safety standard	IEC 61010, double insulation
Certifications	CE, UKCA
Power supply	8 × 1.5 V LR14 batteries or power adapter
Operating temperature	−10 to +40 °C
Storage temperature	−20 to +60 °C
Accuracy reference conditions	18–28 °C; 45–75% RH
Dimensions	202 × 155 × 94 mm
Net weight	1.8 kg

* Accuracy applies to the corresponding measured-resistance interval within the applicable display range for the selected test voltage.

Design and operation

The UT512 uses a large 9999-count LCD with a 30-segment analog bar graph for monitoring measurement values and their variation. A backlight improves readability in poorly lit working areas.

Dedicated controls are provided for insulation resistance testing, AC/DC voltage measurement, PI/DAR testing, timed measurements and comparison testing. Results can be stored internally and transferred to a computer through the USB interface.

Important safety and operating notes

• Insulation resistance testing must only be performed on circuits that are disconnected from their power source and fully discharged.
• The UT512 can generate up to 2500 V DC during insulation testing; test leads and clips must not be touched while high voltage is present.
• Do not short the test leads while high test voltage is being generated.
• The manufacturer specifies limits for prolonged testing at low insulation resistance. When the measured resistance is below 10 MΩ, continuous high-voltage testing must not exceed 10 seconds.
• Do not apply more than 600 V in the AC/DC voltage measurement mode.
• After insulation testing, allow the meter's automatic discharge function to discharge the circuit under test.

Package contents

• UNI-T UT512 insulation resistance tester;
• 2 one-plug-to-alligator-clip test leads – black and green;
• 1 red two-plug-to-alligator-clip test lead;
• 8 × 1.5 V LR14 batteries;
• USB cable;
• PC software media;
• power adapter;
• carrying / tool case. ```