Extech 4-Wire Earth Ground Resistance/Resistivity Tester

Extech 4-Wire Earth Ground Resistance/Resistivity Tester


The Extech 4-Wire Earth Ground Resistance/Resistivity Tester ensures good ground system installation by checking the resistance of the ground as well as the soil resistivity before you install your ground rods.


  • Large Dual Line LCD
  • Autoranging
  • Test Hold Function For Easy Operation
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Why Buy From Fondriest?


This tester includes all hardware necessary to measure Earth Ground Resistance in 3 ranges, from 20 to 2000Ω, and Resistivity from 0.06 to 628kΩm. Electricians and technicians should also check their ground system periodically for predictive maintenance ensuring the resistance level doesn’t exceed the allowed safety level.



  • Automatic I (current) spike check
  • Automatic P (potential) spike check
  • 4-wire, 3-wire, and 2-wire testing
  • Earth resistivity (r) test
  • AC Earth Voltage
  • Data Hold and Auto Power Off
  • Overrange and low battery indication
  • Store/recall up to 200 test results
Notable Specifications:
  • Earth Ground Resistance: 20Ω/200Ω/2000Ω
  • Accuracy: ±(2%rdg+3d)
  • Resolution: 0.01Ω/ 0.1Ω/1Ω
  • Test Current/Frequency: approx. 2mA/820Hz
  • Earth Resistivity: 0.06 to 6.28 kΩm, 0.62 to 62.8 kΩm, 6.28 to 628 kΩm
  • AC Earth Voltage: 0 to 300VAC
  • Accuracy: ±(2%rdg+3d)
  • Dimensions: 9.8 x 7.8 x 4.3"
What's Included:

(1) Tester with built-in hard carrying case

(1) Test leads with alligator clips

(4) Auxillary earth bars

(8) 1.5V AA batteries

Image Part # Product Description Price Stock Order
Extech 4-Wire Earth Ground Resistance/Resistivity Tester GRT350 4-Wire Earth Ground Resistance/Resistivity Tester
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