Clamp-on earth ground tester can measure the ground resistance from 0.01Ω to 1000Ω. With the the clamp on the loop, the meter can get the resistance value safely and quickly without disconnecting circuit ground lines or in needless of auxiliary electrodes. This clamp-on ground resistance tester is durable and accurate, suitable for grounding system measurement of electric power system, telecommunication, meteorology, oil field, building and other fields.
Specification
Model |
ATO-GRT-UT273 |
ATO-GRT-UT275 |
Earth Ground Resistance (Ω) |
0.01Ω~0.099Ω |
±(1%+0.01) |
±(1%+0.01) |
0.1Ω~0.99Ω |
±(1%+0.01) |
±(1%+0.01) |
1.0Ω~49.9Ω |
±(1.5%+0.1) |
±(1.5%+0.1) |
50Ω~99.5Ω |
±(2%+0.5) |
±(2%+0.5) |
100Ω~199Ω |
±(3%+1) |
±(3%+1) |
200Ω~395Ω |
±(10%+5) |
±(10%+5) |
400Ω~590Ω |
±(20%+10) |
±(20%+10) |
600~1000Ω |
±(25%+20) |
±(25%+20) |
Leakage Current (A) |
0.00mA~299mA |
— |
±(2.5%+2mA) |
0.30A~2.99A |
— |
±(2.5%+100mA) |
3A~30A |
— |
±(2.5%+100mA) |
Features |
Display |
9999 counts |
9999 counts |
Auto range |
√ |
√ |
Jaw opening |
28mm |
28mm |
Auto power off |
√ |
√ |
Low battery indication |
√ |
√ |
Data hold |
√ |
√ |
Data storage |
30 sets |
30 sets |
Data recall |
√ |
√ |
LCD backlight |
√ |
√ |
Auto calibration |
√ |
√ |
General |
Power supply |
1.5V battery (LR6) x 4 |
Display size |
47mm x 28.5mm |
Operating temperature |
0℃ ~ 40℃ |
Operating relative humidity |
10%~90%RH non-condensing |
Operating altitude |
≤2000m |
Product weight |
1.5kg |
Product size |
293mm x 90mm x 66mm |
Standard accessories * |
Batteries, test ring, carrying box |
Note: * Batteries are Not Included for air shippment.
Details
Tips: Measuring principle of clamp-on ground resistance tester
1. Resistance measurement principle
The basic principle of measuring ground resistance with a clamp-on earth ground tester is measuring loop resistance. The jaw part of the clamp meter is composed of voltage coil and current coil. The voltage coil provides the excitation signal and induces a potential E on the circuit under test. Under the action of potential E, current I will be generated in the circuit under test. The clamp ground tester measures E and I, and through the formula R=E/I, the measured resistance R can be obtained.
2. Principle of current measurement
The basic principle of measuring the current of the clamp-on ground resistance meter is the same as that of the current transformer. AC current I of the measured wire generates an induced current I1 through the current magnetic ring and current coil of the clamp. I1 is measured by the clamp meter. The measured current I can be obtained by formula I=n* I1 (n is the turns ratio of the coil between the auxiliary side and the original side).