The Fluke 1625 can perform all four types of earth ground measurement including stakeless testing (using 2 clamps only). Stakeless testing allows for the earth ground rod remaining connected, leaving the bonded earth ground system intact during test. This eliminates the need for placing and connecting stakes for each earth ground rod in the system resulting in major time savings. For each type of test, the unit indicates which stakes or clamps need to be connected and the large rotary switch can be used even with a gloved hand.

Brief Specs:

• 3- and 4-pole earth ground measurement.
• 4-pole soil resistivity testing.
• 2-pole resistance measurement AC.
• Selective testing, no disconnection of ground conductor (1 clamps).
• Stakeless testing, quick ground loop testing (2 clamps).
• Earth impedance measurement at 55Hz.
• Automatic frequency control (AFC) (94, 105, 111, and 128Hz).
• ‘R’ measurement – calculates earth ground impedance at 55Hz to more accurately reflect the earth ground resistance that a fault-to-earth experiences.
• Adjustable limits – for quick test result verification.
• Measuring voltage switchable 20/48V.
• Programmable limits, settings.
• Continuity with buzzer.

The Fluke 1630 earth ground clamp utilises the Stakeless testing method where earth ground stakes are no longer necessary. There is no need to disconnect parallel ground rods and find suitable locations for placing auxiliary ground stakes. This saves time and enables earth ground loop tests to be performed in locations where other techniques are not possible.

The Fluke 1630 is placed around the earth ground rod or the connecting cable. A known voltage is induced by one half of the clamp and the current is measured by the other half and the clamp then automatically determines the ground loop resistance at this connection. Applications for the Fluke 1630 include earth ground loop testing in various installations such as high voltage pylons, buildings, cell phone substations, RF transmitters, the inspection of lightning protection systems and leakage current measurement.

Brief Specs:

• A wide ground loop resistance range, from 0.025 Ω to1500 Ω, to satisfy all requirements
• Large jaw opening of 35 mm (1.38 in) for tests on ground conductors and/or equipotential bus bars
• Measurement of ground leakage current, from 0.2 mA to 1000 mA, without needing to disconnect – ideal for system troubleshooting
• Wide ac current measurement range from 0.2 A to 30 A allows one instrument for multiple applications
• Continuity loop test – quickly assess whether resistance is less than 40 Ω, with audible alarm
• User-defined HI / LO Alarm limits, for rapid measurement evaluation
• Handy “Display-Hold” button for capturing readings in hard-to-reach places
• Time saving memory function automatically records and stores measured values
• Automatic self calibration ensures correct measurement every time

The LEM Saturn GEO X Earth 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.

Brief Specs:

• 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