
UNI-T UT505B Insulation Resistance Tester & Multimeter
Overview
The UT505B is the wider-range model in the UT505 pair: a CAT IV 600 V insulation tester and True-RMS digital multimeter in one handheld, reading insulation resistance up to 200 GΞ© at test voltages from 50 V to 1000 V to IEC 61557. It adds an automatic fuse check to the combination, so the meter verifies its own current-input fuse before you rely on a reading.
Insulation testing includes Polarization Index and DAR diagnostics, stepped-voltage testing, and automatic discharge; the 6000-count multimeter covers AC/DC voltage, resistance, capacitance, and frequency, with 99 result groups stored on-board. It's backed by UNI-T's nearly 40 years of test-meter manufacturing.
Key Features
- Insulation resistance up to 200 GΞ©, accuracy Β±(1.5%+5)
- Test voltages: 50 V, 100 V, 250 V, 500 V, 1000 V (IEC 61557)
- True-RMS 6000-count digital multimeter built in
- Automatic fuse check
- AC/DC voltage to 600 V; capacitance, frequency, low and general resistance
- PI and DAR insulation diagnostics
- Stepped-voltage testing and automatic discharge
- 99-group data storage; CAT IV 600 V
UT505B Details
Two Instruments in One
Like the UT505A, the UT505B pairs a 1000 V insulation tester with a full True-RMS multimeter, so one handheld covers insulation testing and the voltage, resistance, capacitance, and frequency measurements that go with it.
Insulation Testing to 200 GΞ©
A 200 GΞ© measurement range β ten times the UT505A β keeps high-resistance insulation on-scale, with five test voltages from 50 V to 1000 V and IEC 61557 compliance for motor, cable, and switchgear work.
Automatic Fuse Check
The UT505B verifies its own current-input fuse automatically, so a blown fuse can't quietly turn a current measurement into a misleading reading β a useful safeguard in daily field use.
PI, DAR & Stepped Voltage
Timed PI and DAR diagnostics and stepped-voltage testing reveal moisture, contamination, and marginal insulation that a single fixed-voltage reading would pass.
Safety & Field Build
Automatic discharge clears stored charge after each test, the CAT IV 600 V rating suits distribution work, and 99 result groups store on-board for later review.
Compare the UT505 Series
| UT505A | UT505B | |
|---|---|---|
| Max insulation resistance | 20 GΞ© | 200 GΞ© |
| Auto fuse check | β | Yes |
Applications
Combined insulation and electrical testing on motor windings, cables, and switchgear where a wider 200 GΞ© range is needed; preventive maintenance with one tool for both jobs; and field troubleshooting that moves between insulation testing and routine multimeter measurements.
Frequently Asked Questions
How high does the UT505B measure insulation resistance?
Up to 200 GΞ© β ten times the range of the UT505A.
What is the automatic fuse check?
The meter verifies its own current-input fuse automatically, so a blown fuse won't produce a misleading current reading.
Is the UT505B also a multimeter?
Yes β a True-RMS 6000-count multimeter with AC/DC voltage, resistance, capacitance, and frequency, in addition to insulation testing.
Warranty
This product includes a standard 1-year warranty covering manufacturing defects and component failures under normal use conditions.
UNI-T stands behind every product we sell. If you experience any issues within the warranty period, our US-based support team is here to help with troubleshooting, repair, or replacement.
| Max Test Voltage | 1000V |
|---|---|
| Max Resistance | 200GΞ© |
| Short Circuit Current | <2mA |
| AC Voltage | 600V, Β±(1.5%+5) @ 0V~600V |
| DC Voltage | 600V, Β±(2%+3) @ 0V~600V |
| CAT Rating | CAT IV 600V |
| Instrument Type | Insulation Tester |
Features
- Polarization Index
- Auto Discharge
- Comparison Function
- Auto Ranging
- High Voltage Alarm
- Auto Power Off
- Audible Visual Alarm
- Time Setting Function
- Data Hold
- Analog Bar Graph
- Backlight
- Low Battery Indication
- True RMS
- Comparison Measurement
- PI / DAR
- Auto Fuse Check
Full specifications (18)
| Details | |||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Insulation Resistance |
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| Resistance Accuracy | Β±(1.5%+5) | ||||||||||||||||||||||||||||||||||||||||||||
| Step Voltage | 10% steps at 50%~120% of range | ||||||||||||||||||||||||||||||||||||||||||||
| Data Storage | 99 | ||||||||||||||||||||||||||||||||||||||||||||
| Test Voltage Accuracy | 0% β 20% | ||||||||||||||||||||||||||||||||||||||||||||
| Charge Current | 2mA | ||||||||||||||||||||||||||||||||||||||||||||
| Capacitance | 500ΞΌF, Β±(5%+5) @ 100pF~500ΞΌF | ||||||||||||||||||||||||||||||||||||||||||||
| Leakage Current | Β±(10%+3) | ||||||||||||||||||||||||||||||||||||||||||||
| Features | |||||||||||||||||||||||||||||||||||||||||||||
| Frequency | 1kHz, Β±(0.1%+3) @ 45~1kHz | ||||||||||||||||||||||||||||||||||||||||||||
| Count | 6000 | ||||||||||||||||||||||||||||||||||||||||||||
| DAR | 60s/15s and 60s/30s | ||||||||||||||||||||||||||||||||||||||||||||
| General Resistance | Β±(3%+3) | ||||||||||||||||||||||||||||||||||||||||||||
| Low Resistance | Β±(1.5%+3) | ||||||||||||||||||||||||||||||||||||||||||||
| General Information | |||||||||||||||||||||||||||||||||||||||||||||
| Battery | 1.5V AA Γ 6 | ||||||||||||||||||||||||||||||||||||||||||||
| Dimensions (WΓHΓD) | 103 Γ 225 Γ 59 mm | ||||||||||||||||||||||||||||||||||||||||||||
| Weight | 630 g | ||||||||||||||||||||||||||||||||||||||||||||
| Warranty | 1 year | ||||||||||||||||||||||||||||||||||||||||||||
| Certifications | CE|cETLus | ||||||||||||||||||||||||||||||||||||||||||||
Data Sheets and Manuals
- Not currently available. Contact us with questions.