The LEM Saturn GEO X earth ground tester is a compact, field-rugged and extremely easy to use instrument. It is able to perform standard 3- and 4-pole earth resistance measurements as well as accurately measuring individual earth electrode resistances in single and meshed earthed systems without disconnecting any parallel electrodes. One specific application of this capability is the quick and accurate measurement of power pylon grounds. The Saturn GEO X also incorporates an automatic frequency control (AFC) to minimise interference. Before measuring, the instrument identifies existing interference and selects the most appropriate a measurement frequency to minimise the interference effect. Another feature is microprocessor controlled automatic measurements including checking probe hookup to ensure measurements are taken correctly and measuring all probe ground resistances to ensure reliable, repeatable results. Probe resistance and auxiliary earth resistance are also measured and displayed. All measured data, including the time that the measurement was taken, can be uploaded or printed via an RS-232C interface.

• Earthing resistance 3-pole and 4-pole of 0.001 ...300k, with voltages of 20 V/48 V AC, frequencies of 94, 105, 111, 128 Hz or AFC (Automatic Frequency Control) and automatic test of test lead connection and adjustable limit values
• Resistance 2-pole AC 0.001 ...300 k
• Noise voltage up to 50 V, noise frequency
• Measurement of the earthing impedance of electricity pylons
• Selective measurement of individual earth electrode resistance in interlinked or parallel ground systems (i.e. power pylons, grounding grids, lightning protection systems) without influence from other grounds.
• Low resistance 2- and 4-pole 0.001 ...3 k with automatic polarity reversing and high short-circuit current4
• Display illumination
• Serial interface