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Handheld Clamp-On Ground Resistance Tester


  • Measures earth resistance without need to disconnect from the electrical system or need for auxillary ground electrodes or reels
  • Ground Resistance is auto-ranging from 1 to 199Ω
  • Current Measurement is auto-ranging from 1mA to 40A
  • Ground voltage indication - warns of unsafe conditions
  • Clamping diameter of 1.4" (35 mm) with large jaw design
  • Stores up to 300 measurements
  • Includes a hard carrying case, calibration loop, four 1.5V AA batteries and a user manual


Part Number EST401
Ground Resistance Measurement Range 0.01 – 1,500.00 Ω
Ground Resistance Resolution 0.001 – 50.000 Ω
Ground Resistance Accuracy Approx. 1.5% - 25%
Current Measurement Range 0.20 mA – 39.99 A
Current Measurement Resolution 1 µA – 10 mA
Current Measurement Accuracy +/- 2%
Current Measurement Frequency 47 – 800 Hz
Operating Frequency 2,083 Hz
Loop Impedance Measurement 10 to 100μH; 100 to 500μH

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