| Basic Functions | Range | Best Accuracy |
| Model | UT523A | |
| Earth resistance | 0.00Ω～19.99Ω | ±(2%+5) |
| 20.0Ω～199.9Ω | ±(2%+5) | |
| 200Ω～1999Ω | ±(2%+5) | |
| 2.00kΩ～19.99kΩ | ±(2%+5) | |
| 20.0kΩ～210.0kΩ | ±(2%+5) | |
| Soil resistivity | 0.00Ωm～99.99Ωm | Decided by measuring precision of R: (ρ=2πaR a:1 m～100m, π=3.141) |
| 100.0Ωm～999.9Ωm | ||
| 1000Ωm～9999Ωm | ||
| 10.00kΩm～99.99kΩm | ||
| 100.0kΩm～999.9kΩm | ||
| 1000kΩm～9000kΩm | ||
| Earth voltage | AC 0.00～750V | ±(2%+5) |
| Testing resistance | 128Hz/111Hz/105Hz/94Hz(AFC) | √ |
| Features | ||
| Measuring method | Earth resistance: rated current pole changing method with Max 20mA measuring current; | √ |
| soil resistivity: quadrupole method (Wen-Na method ); | ||
| earth voltage: average rectifier (between P(S) and ES interfaces) | ||
| Short-circuit testing current | AC 30mA max | √ |
| Open-circuit testing voltage | AC 40V max | √ |
| Auto range | √ | |
| Distance between electrodes | 1m～200m can be set. | √ |
| Testing voltage waveform | Sine wave | √ |
| Line voltage | Measure when the voltage is below 750V AC | √ |
| Low battery indicator | ≤7.5V | √ |
| Data hold | √ | |
| Alarm function | √ | |
| RS232 interface | √ | |
| Withstand voltage | AC 3700V/rms(between circuit and case) | √ |
| LCD backlight | √ | |
| Data storage | 300 groups | √ |
| Auxiliary earth resistance test | 0.00KΩ～30kΩ(100R+rC<50kΩ, 100R+rP<50kΩ) | √ |
| Overload protection | Earth resistance measurement: input 280V AC between C(H) and E, P(S) and ES for 3s | √ |
| Interference test | Auto identify interference signals, when interference voltage is higher than 5V, the symbole NOISE is displayed. | √ |
| Measuring time(s) | More than 5000 times (perform short circuit test once, and again after 30s) | √ |
| Insulation resistance | Above 20MΩ (500V between circuit and case) | √ |