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 G 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 G, accuracy (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 G
A 200 G measurement range ten times the UT505A 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 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 G | 200 G |
| Auto fuse check | Yes |
Applications
Combined insulation and electrical testing on motor windings, cables, and switchgear where a wider 200 G 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 G 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 a True-RMS 6000-count multimeter with AC/DC voltage, resistance, capacitance, and frequency, in addition to insulation testing.
Specifications
| Test Voltages | 50 V / 100 V / 250 V / 500 V / 1000 V |
| Insulation Resistance | 0.01 M to 200 G |
| IR Accuracy | (1.5% + 5) |
| DC Voltage | 0 to 600 V, (2% + 3) |
| AC Voltage | 0 to 600 V, (1.5% + 5) |
| Frequency | 45 to 1 kHz, (0.1% + 3) |
| Capacitance | 100 pF to 500 F, (5% + 5) |
| Low Resistance | 0.01 to 20 k, (1.5% + 3) |
| General Resistance | 0.01 k to 10 M, (3% + 3) |
| Display Count | 6000 |
| True RMS | Yes |
| PI / DAR | Yes |
| Step Voltage | Yes |
| Auto Discharge | Yes |
| Data Storage | 99 groups |
| Auto Fuse Check | Yes |
| Compliance Standard | IEC 61557 |
| Safety Rating | CAT IV 600 V |
| Power | 6 1.5 V (LR6) |
| Dimensions (W H D) | 103 225 59 mm |
| Weight | 630 g |
Documentation
- UT505B Datasheet
- UT505B User Manual
