UT276A+ UT278A+ Clamp Earth Ground Tester  UT270 series can quickly and safely measure the grounding system without disconnecting circuit ground lines or the need of auxiliary electrodes. It can measure resistance from 0.01Ω with a resolution of 0.001Ω. UT278A+ can also measure leakage current up to 20A. These clamps'double insulation design makes them durable tools for outdoor work and e& 64256;ective in blocking interference signals from the environment. Grounding resistance measurement in electricity, telecommunication, meteorology, oilfield, architecture and industrial electric equipment        Features& 65306;        1. Wide ground loop resistance measurement range (0-1200Ω), which can meet most of the user's measurement requirements; 2.32mm large jaws, can test various grounding levels and equipotential busbars; 3. AC current measurement range 0-20A(UT278A+ only), and can detect leakage current below 300mA, can be measured without disconnection, which is very suitable for system fault diagnosis; 4. User-defined HI/LO alarm limits; 5. Data retention function for obtaining stable readings in places that are difficult to access; 6. Time-saving storage function is convenient for users to consult the test data to draw a table report after measurement; 7. With CAT III 300V safety level                                  Specifications     Range     Resolution     Accuracy           Earth Ground Resistance (Ω)     0.010Ω-0.099Ω     0.001Ω     ±(1%+0.01Ω)           0.1Ω-0.99Ω     0.01Ω     ±(1%+0.01Ω)           1.0Ω-49.9Ω     0.1Ω     ±(1%+0.1Ω)           50.0Ω-99.5Ω     05Ω     ±(1.5%+0.5Ω)           100Ω-199Ω     1Ω     ±(2%+1Ω)           200Ω-395Ω     5Ω     ±(5%+5Ω)           400Ω-590Ω     10Ω     ±(10%+10Ω)           600Ω-880Ω     20Ω     ±(20%+20Ω)           900Ω-1200Ω     30Ω     ±(25%+30Ω)           Leakage current (A)     0.00mA-9.95mA     0.01mA     ±(2.5%+1mA)           10.0mA-99.0mA     0.1mA     ±(2.5%+5mA)           100mA-300mA     1mA     ±(2.