The UT625A/UT625B Low Resistance Tester measures contact and loop resistance of switchgear with 100A/200A DC test currents. It directly reads resistance values, stores up to 200 test records, and uploads data to PC for storage/printing.
Featuring high accuracy and stable performance, it’s widely used in power systems, rail transit, new energy, etc., for loop resistance testing of high-voltage switches, transformers, busbars, cable joints, grounding devices, combiner boxes, and inverters.
Features
- Resistance:
i. UT625A: 0.1uΩ~1000mΩ
ii. UT625B: 0.1uΩ~2000mΩ - Test current:
i. UT625A: 5A~100A, stepping current: 5A/10A
ii. UT625B: 5A~200A, stepping current: 5A/10A - Four-wire accuracy measurement
- Data transmit (via USB cable): PC software analysis
- Built-in thermal printer: to print the testing data, recordings
- Comparison test: arbitrary setting of comparison values
- Test time: 10s~60s, 1s stepping time
- OL indication: if the reading <0.1uΩ，it displays 0.0uΩ; if the reading >Max range, it displays OL
- 200 set data storage
- Data storage: auto save/manual save/ Circular save
- Adjustable backlight: 5 levels
Specifications
| Model | UT625A | UT625B | ||
| Current (customizable) | Range/Resolution | Accuracy | Range/Resolution | Accuracy |
| 200A | / | / | 0.1uΩ~1999.9uΩ: 0.1uΩ | ±(0.4%rdg+0.04%FS) |
| 100A | 0.1uΩ~1999.9uΩ: 0.1uΩ | ±(0.4%rdg+0.04%FS) | / | / |
| 100A | 2.000mΩ~9.999mΩ: 0.001mΩ | 2.000mΩ~9.999mΩ: 0.001mΩ | ±(0.4%rdg+0.04%FS) | |
| 50A | 10.00mΩ~99.99mΩ: 0.01mΩ | 10.00mΩ~99.99mΩ: 0.01mΩ | ||
| 5A | 100.0mΩ~499.9mΩ: 0.1mΩ | ±(0.4%rdg+0.6%FS) | 100.0mΩ~499.9mΩ: 0.1mΩ | ±(0.4%rdg+0.6%FS) |
| 500mΩ~1000mΩ: 1mΩ | 500mΩ~2000mΩ: 1mΩ | |||
| Functions | 1. To test the contact resistance of low/medium/high-voltage circuit breakers; 2. To test bus connections and other high-current connection points. | |||
| Resistance measurement | 0.1uΩ~1000mΩ: 0.1uΩ | 0.1uΩ~2000mΩ: 0.1uΩ | ||
| Test method | 1, Four-wire Kelvin test; 2, Separation of current and voltage electrodes eliminates internal wiring impedance and contact resistance for more accurate measurements; 3, Minimizes measurement errors to achieve high-precision results when measuring low-resistance components. | |||
| Noise suppression | At 100 mV differential pressure, the noise frequency of the test lead is 50-60 Hz. | |||
| Stepping test current | 1. 5A~ 100A DC ; 2. Stepping current:5A or 10A | 1. 5A~ 200A DC ; 2. Stepping current:5A or 10A | ||
| Test time | 10S、20S、30S、60S, stepping time: 1s. | |||
| Test duration | The maximum continuous testing time for a single run is 60 seconds. | The maximum continuous testing time for a single run is 60 seconds. | ||
| Resistance value comparison | 1, Pre-set value: 0.000~9999.9mΩ; 2,Compare measured and set resistance values, automatically display “PASS” or “FAIL” | |||
| Over range indication | 1, Low Limit Alert: When the loop resistance measurement is low limit, the measurement interface will display “LO”; 2, Over-limit indication: when the loop resistance measurement exceeds the limit, the measurement interface will display “OL”; | |||
| Self-inspection | 1, Yes, Self-calibration via standard accessory “shunt” to verify measurement accuracy and ensure reliable data. 2, UT625A: 750μΩ; UT625B: 375μΩ | |||
| Open circuit voltage | UT625A (voltage: 5V DC) UT625B (voltage: 10V DC) | |||
| Overheating protection | ✔ | |||
| Output power | Measurement power ≤ 250W | |||
| Display | 7 inch color LCD | |||
| Printer | Built-in thermal printer | |||
| Input power supply | AC 198V~242V（50/60Hz） | |||
| Data Communication | Supports PC connection (via USB cable). 1, Real-time analysis; 2, Historical data review; 3, Excel report generation. | |||
| Data storage | 200 sets; auto/manual save, Circular save | |||
| Backlight | 5 levels adjustable backlight | |||
| Low battery indication | ✔ | |||
| Working environment | -20°C~+50°C ; <85% R.H., no condensation | |||
| Storage environment | -30°C~+60°C ; <85% R.H., no condensation | |||
| Characteristic | ||||
| Standard accessories | 1, 4-wire test clip (red and black) 1 pair; 2, Ground cable 1pcs; 3, Shunt 1pcs; 4, USB cable 1pcs; 5, power adapter(AC) 1pcs; 6, Thermal printer paper 1 roll; 7, Cloth bag 1pcs; 8, Quick start guide 1pcs; | |||
| Product dimension | 357mm*293mm*193mm | |||
| Product net weight | UT625A: 6.4Kg; UT625B: 7.5Kg | |||
| Standard package dimension | 460mm*410mm*385mm | |||
| Standard package weight | UT625A: 10.68Kg; UT625B: 12.7Kg | |||
