Ground resistance meter 3-electrode measurement on the 3151 gives greater precision! Ground resistance measurement involves factors that are not encountered during ordinary resistance measurement, such as polarization of the earth, the influence of grounding current due to leak current and grounding voltage, and the influence of auxiliary grounding resistance. The 3151 is able to make more accurate measurements more safely under difficult conditions because it uses the alternating current potentiometer method to provide measurement accuracy, and because it contains features such as an auxiliary grounding resistance check feature and measurement frequency switching. SPECIFICATIONS:

• Ground resistance 10 ohm (0 to 11.5 ohm), 100 ohm (0 to 115 ohm), 1000 ohm (0 to 1150 ohm), 3 ranges (±2.5 % f.s.)
• Ground voltage 30 V (0 to 30 V), (±3.0 % f.s.)
• Operating method AC potentiometer method
• Open circuit voltage 50 V AC max.
• Measurement current 15 mA AC max. (3 mA AC max. when using the two electrode method)
• Measurement frequency 575 Hz (with 3a or 2a selected) or 600 Hz (with 3b or 2b selected)
• Power supply R6P(AA) manganese batteries × 6 (at least 500 operations), or LR6(AA) alkaline batteries × 6 (at least 1400 operations) Note:30 seconds measurement, 30 seconds off operating time
• Dimensions, mass 164 mm(6.46 in)W × 119 mm(4.69 in)H × 88 mm(3.46 in)D, 800 g (28.2 oz)
• Accessories AUXILIARY EARTHING RODS 9214 (2), MEASURING CABLE 9215 (black 5 m(16.41 ft), yellow 10 m(32.81 ft), red 20 m(65.62 ft), one each CABLE WINDER 9216 × 3), CARRYING CASE 9393 (1)