UNI-T UT501B Insulation Resistance Tester
UNI-T UT501B Insulation Resistance Tester is a professional insulation testing instrument designed for reliable electrical maintenance and troubleshooting. It supports insulation resistance testing with 250V, 500V, and 1000V test voltages, low resistance measurement, and AC voltage detection up to 600V. The tester features PI and DAR calculations, auto ranging, LCD backlight, high-voltage warning, automatic discharge, and test voltage display. Its rugged design and compliance with IEC standards make it suitable for electricians, maintenance engineers, industrial equipment inspection, and power system applications.
Features
- Performs insulation resistance testing with selectable 250V, 500V, and 1000V test voltages.
- Measures insulation resistance up to 5GΩ with high accuracy.
- Includes PI (Polarization Index) measurement for insulation condition assessment.
- Supports DAR (Dielectric Absorption Ratio) calculations for advanced insulation analysis.
- Measures low resistance from 0.01Ω to 200Ω for continuity and resistance testing.
- Measures AC voltage from 30V to 600V for electrical verification.
- Features auto ranging for faster and easier measurements.
- Equipped with LCD backlight for improved visibility in low-light environments.
- Provides high-voltage indication and buzzer alarm for enhanced operator safety.
- Automatically discharges stored voltage after insulation testing for added protection.
- Displays the actual test voltage during measurements for greater accuracy.
- Includes low battery indication to ensure reliable operation.
- Meets IEC 61557 safety and performance requirements.
- Powered by six AA batteries for convenient portable operation.
Specifications
| Parameter | Details |
|---|---|
| Brand | UNI-T |
| Model | UT501B |
| Insulation Test Voltages | 250V, 500V, 1000V |
| Insulation Resistance Range (250V) | 0MΩ-99.9MΩ: ±(3%+5); 100MΩ-5GΩ: ±(5%+5) |
| Insulation Resistance Range (500V) | 0MΩ-99.9MΩ: ±(3%+5); 100MΩ-5GΩ: ±(5%+5) |
| Insulation Resistance Range (1000V) | 0MΩ-99.9MΩ: ±(3%+5); 100MΩ-5GΩ: ±(5%+5) |
| Load Current | 250V(R=250kΩ)1mA ±10%; 500V(R=500kΩ)1mA ±10%; 1000V(R=1MΩ)1mA ±10% |
| Short-Circuit Current | <2mA |
| Low Resistance Range | 0.01Ω-200Ω, ±(2%+3) |
| AC Voltage Range | 30V-600V, ±(2%+3) |
| Display Count | 2000 Counts |
| DAR | 60s/15s and 60s/30s |
| PI | Supported |
| Auto Range | Yes |
| Low Battery Indication | Yes |
| LCD Backlight | Yes |
| Light Alarm | Yes |
| Buzzer Alarm | Yes |
| High Voltage Indication | Yes |
| Overload Indication | Yes |
| Auto Discharge | Yes |
| Test Voltage Display | Secondary Display |
| 10MΩ Internal Resistance Test | Yes |
| Power Supply | 6×1.5V(LR6) Batteries |
| Display Size | 70.6mm × 34mm |
| Product Color | Red and Grey |
| Net Weight | 500g |
| Dimensions | 150mm × 100mm × 71mm |
| Standard Accessories | Batteries, Test Leads, Alligator Clips, Gallus |








