ST-1520 3 Wire Digital Earth Resistance Tester

  • 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.
  • Auto power off function.
  • The timer operates automatically for about three to five minutes when the "PUSH BUTTON SWITCH" and "TIMER ON BUTTON" are pressed together.
  • This will keep test "ON" for the duration of the timer.
  • Timer for test function (count 3-5 minutes).
  • Battery operated.
  • Data hold function.
  • Indication: Low battery. Data hold. Over range.
  • Small and light weight.
  • Calibration performed with supplied test leads.


  • Earth resistance: 0-20Ω / 0-200Ω / 0-2kΩ.
  • 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. 0-2kΩ: 1Ω.
  • Testing frequency: 820 Hz.
  • Measuring system: Earth Resistance by constant current inverter 820Hz approx. 2mA.
  • Open circuit indication: LED will be unlit.
  • Display: 3½ digit (2000 counts).
  • Dimensions: 163(L) × 100(W) × 50(D)mm.
  • Weight (battery included): Approx. 480g.
  • Power source: 1.5V (AA) × 6.
  • Safety standards: EN 61010-1 CAT III 200V. EN 55022.