The Ground Resistance Tester Model 6471 is a portable measurement instrument designed to measure Ground Resistance using 2 current clamps (no auxiliary rods). Other test methods provided are: Ground Resistance (3-Pole or 4-Pole), Ground Coupling, Bond Resistance, Selective Ground Resistance and Soil Resistivity (Wenner or Schlumberger method). The Model 6471 measures from 0.01 to 99.99kΩ and is auto-ranging, automatically seeking out the optimum measurement range and test current. Easy-to-use – Simply connect the leads, select the test mode, press Start and read the results.  Up to 512 test results can be stored in internal memory for later recall to the display or download to a PC via DataView software. The Model 6471 is Cat. IV rated to 50V and is over voltage protected to more than 250VAC against accidental connection to live circuits. The voltage is also displayed on screen. Additional features of the 6471 include a heavy-duty field case sealed against dust and water when closed (the test button is also sealed against the elements); manual and automatic test frequency selection from 41 to 513Hz; user selectable 3-Pole Fall-of-Potential or 4-Pole Soil Resistivity test methods and user selectable 2-Pole or 4-Pole Bond Resistance test method. The Model 6471 is rugged, easy-to-use and ideal for maintenance crews performing numerous tests. It exceeds mechanical and safety specifications for shock, vibration and drop tests per IEC standards. The adjustable test frequency provides for rejection of high levels of interference, allowing it to be used under difficult conditions such as high stray currents that normally affect accuracy.

Applications:

• 3-Point measurements of resistance to ground on ground rods and grids
• 4-Point tests of soil resistivity measurements
• Touch and Step potential testing measurements
• 2- or 4-Wire tests for continuity tests on bonding or on grounding systems
• Earth Coupling measurement and display

The AEMC Model 6471 is Available in Complete Kit Form:

AEMC 6471 Kit – 300 ft Multi-Function Ground Resistance Tester – includes meter, set of two SR182 current probes, rechargeable NiMH batteries, optical USB cable, power adapter 110/240V with power cord 115V US, two 300 ft color-coded leads on spools (red/blue), two 100 ft color-coded leads (hand-tied, green/black), four T-shaped auxiliary ground electrodes, set of five spaded lugs, one 100 ft AEMC tape measure, DataView software, ground tester workbook CD, carrying bag for meter and carrying bag for kit.  View and Purchase this convenient Kit HERE

AEMC Instruments manufactures professional electrical test and measurement instruments for the industrial, commercial and utility marketplace. Founded in 1893, their products are backed by over 100 years of experience in test and measurement equipment, and encompass the latest international standards for quality and safety. AEMC is the industry leader in current measurement probes, ground resistance testers and insulation resistance testers. Their full product line also includes clamp-on meters, ratiometers, power meters, harmonic power meters, data loggers, lightmeters and numerous other electrical test tools.

These 1 kV units were designed based on Megger’s extensive knowledge of insulation testing (100+ years of experience) and significant feedback from actual end users.

The MIT400 units include:

Megger’s patented digital/analog display with real-time pointer movement. Other manufacturer’s units do not offer a true analog arc display with pointer travel. Some offer only a digital readout while others offer an analog bargraph that does not provide any of the information gained from pointer travel.

Industry best (by far) measurement sensitivity, allowing users to identify potential problems early before they become bigger problems. The MIT400 Series’ measurement sensitivity (up to 200 GΩ) dwarfs anything found on comparable units.

CAT IV, 600 V safety rating on BOTH insulation and continuity  measurement ranges. Some competitive units claim a CAT IV, 600 V safety rating, but have no rating on the continuity measurement.

Industry best IP54 (ingress protection) rating (protection against splashing water from any direction). Some competitive units have an IP rating of IP40, which means they are not protected against liquid ingress at all.

How important is the electrical equipment you intend to test?

The MIT400 Series offers the highest measurement range available, which will allow you to identify problems early. Additionally, the real-time analog arc provides an experienced user key additional information.

In what types of environments are you testing?

The MIT400 Series has the highest IP rating of the available instruments. They can be used effectively in the harshest conditions.

How important is safety?

In addition to being CAT IV, 600V rated, the MIT400 Series units (like all Megger insulation testers) are designed with Megger’s Intelligent Safety System, which includes specific protection circuitry to ensure that, in the case of incorrect connection or accidental connection to unsuitable circuits, no damage will occur to the instrument, and the operator is fully protected.

Do you want to purchase a true insulation tester?

All Megger models are based on an insulation tester “footprint” and are designed for insulation testing applications. Some competitive units are multimeters first with insulation testing capability added second.

Application Guru, Jeff Jowett of Megger answers the following question.

Q:  What is the significance of line powered or battery powered?

A: Battery power is safe and more convenient. But in the “old days,” batteries developed a bad reputation for unreliability and rapid drain. Modern conservation techniques in well-designed equipment have eliminated these shortcomings, making battery-powered units more portable and, of course, not dependent on site power, hence more amenable to field work and construction environments. They also provide a much better regulated power source, free from the effects of transients and other line disturbances. Furthermore, as a self-contained power source, they can be designed so as to be well within safety parameters, which is difficult to guarantee with line power that is connected to the North American grid! A common misconception is that line power somehow provides a “better” (i.e. more robust) test. The only thing that all that extra power might get you is arc flash! It does NOT provide a more reliable test.

The only disadvantage that batteries do have is that they eventually go dead. This leaves battery power open to “human error.” Dual-powered units, both line and battery operated, therefore offer the best of all worlds. To paraphrase a former light heavyweight champion, Tommy Loughran, “Use batter power when you can, line power when you must.”