1120 ER 3 Wire Digital Earth Resistance Tester


1120 ER 3 Wire Digital Earth Resistance Tester is suitable for the testing of single earth electrodes such as lightning conductors and other small earthing systems. The resistance of conductors such as continuity and conduit coupling joints can also be measured.

  • Waterproof: IP54.
  • Capable of measuring earth resistance and earth voltage.
  • 2mA measuring current permits the testing of earth resistance without tripping earth leakage current breakers in the circuit under test.
  • The test leads are supplied as standard accessories for simplified two-wire measuring system.
  • 0Ω adjustment.
  • Battery operated.
  • Data hold function / indication.
  • Low battery indication.
  • Over range indication: “1”(MSD).


  • Earth resistance: 0-20Ω / 0-200Ω / 0-2000Ω.
  • Earth resistance Accuracy: ±(2%rdg+2dgt) or ±0.1Ω, which is greater.
  • Earth voltage: 0-200 Vac(40-500Hz).
  • Earth voltage Accuracy: ±(1%rdg+2dgt).
  • Earth resistance resolution: 0-20Ω: 0.01Ω. 0-200Ω: 0.1Ω. 0-2000Ω: 1Ω.
  • Measuring system: Earth resistance by constant current inverter 820 Hz, 2mA approx.
  • Open circuit indication: LED will be unlit.
  • Display: 3½ digit (2000 counts).
  • Dimensions: 175(L) × 85(W) × 75(D)mm.
  • Weight (battery included): Approx. 600g.
  • Power source: 1.5V (AA) × 6.
  • Safety Standard: EN 61010-1 CAT III 200V. IEC 61557-1. IEC 61557-5. EN 61326-1.