Chauvin Arnoux CA 6471 Earth and Resistivity Tester

CA 6471 is a portable earth and resistivity tester from Chauvin Arnoux for earth-electrode resistance by the 3-pole and 4-pole methods, selective earth measurement with a clamp, earth loops with two clamps, soil resistivity and low-ohm 2-wire or 4-wire resistance, all in a field case with a back-lit display and a built-in battery charger.

Earthing measurements from a single field instrument

The manual describes the CA 6471 as a complete portable instrument for earth measurements and soil-resistivity measurements. A seven-position switch selects the function, a six-key keypad handles the secondary functions and one START/STOP button runs the test. The 108 x 84 mm back-lit LCD shows three levels of numerical data at once, so the result and its influence quantities can be read together.

In automatic mode you set the switch, connect the leads, press START and the instrument stops by itself. In manual (expert) mode the CONFIG key changes the test frequency, voltage and current direction, even during a measurement.

Measurement functions listed in the manual

• 2-wire and 4-wire resistance in the mΩ position, with lead compensation up to 5 Ω and an adjustable alarm between 1 and 999 Ω.
• 3-pole earth measurement with two auxiliary electrodes; the manual recommends the 62 % method.
• 4-pole earth measurement for very low values, with ten times better resolution than 3P and no lead compensation.
• Coupling of earth resistances and selective earth resistance with a C182 or MN82 clamp on terminal ES.
• Soil resistivity by the Wenner or Schlumberger method with programmable distances d and A.
• Earth resistance with two clamps, at 1611 Hz automatic or 128 to 1758 Hz manual.
• Noise detection, smoothing, object/test memory and GTT software for configuration and data transfer.

Technical specification

Resistance and earth measurement ranges

General specification

Choosing the measurement method

Use 3P for routine rod and plate electrodes, 4P when the expected value is below a few ohms or lead resistance matters, selective 4P with a clamp when the electrode cannot be disconnected from the rest of the earthing system, and the 2-clamp method when no auxiliary rods can be driven, for example inside a built-up site. Soil resistivity is the tool for designing a new earthing grid and for choosing where to place electrodes.

Confirm which kit (100 m or 150 m) and which clamp (C182, 52 mm, or MN82, 20 mm) you need when requesting a quotation.

Field procedure from the manual

For a 3P test, drive electrodes H and S in a straight line with the electrode under test, place S at 62 % of the distance to H, and keep the H to S spacing above 30 m. Unwind the full cable length, keep cables apart and avoid loops or runs parallel to metal conductors. To prove the reading, move S by 10 % of d each way; the three values should agree within a few percent, otherwise increase d.

Never measure on conductors that may be connected to the network or on earth conductors that are not disconnected. The manual notes that rod potentials can differ near a faulty installation or during thunderstorms, and leaves the decision to continue to the operator. Charge only between 0 and 40 °C with the supplied charger.

Earthing work in Oman and the GCC

Substation, refinery, solar-farm and telecom-tower earthing is commonly verified at commissioning and again after maintenance. In arid or sandy ground, high electrode contact resistance is typical; the manual advises driving rods deeper or wetting the soil around them, and the instrument reports when auxiliary-electrode resistance is too high.

Accessories and spares

The manual lists 100 m and 150 m earth and resistivity kits, the continuity kit, C182 and MN82 clamps with 2 m cables, a cigarette-lighter charging adapter, DataView software, an optical/RS cable and a GB power cord. Spares include 0.63 A, 250 V, 5 x 20 mm, 1.5 kA fuses, the 18 V / 1.5 A charger, the 9.6 V NiMH pack and the carrying bag. Other instruments are in the Portable Test & Measurement category.

Frequently asked questions

Which earth methods does the CA 6471 support?

3-pole and 4-pole earth, coupling of earth resistances, selective earth with a clamp, earth with two clamps and soil resistivity by the Wenner or Schlumberger method.

What clamps are used with it?

The C182 (52 mm) and MN82 (20 mm) clamps, each delivered with a 2 m cable for terminal ES. The instrument cannot tell which one is connected, so observe the MN82 limits yourself.

What test frequencies can be selected?

41 to 513 Hz for earth measurements and 41 to 128 Hz for soil resistivity; the 2-clamp method uses 1611 Hz automatically or 128, 1367, 1611 and 1758 Hz manually.

What distance is allowed for Wenner spacing?

The manual states that distance d must be between 2 and 30 m, with electrodes on a straight line and driven to a depth below one third of d.

Is Seven Star LLC a Chauvin Arnoux distributor?

No, we are an independent supplier in Muscat and supply Chauvin Arnoux items on request rather than acting as a Chauvin Arnoux channel partner.

Documents and quotation

For quotation, send your required quantity and destination. The Chauvin Arnoux user manual for CA 6471 is provided below the description on this page. Seven Star LLC works as an independent supplier from Muscat. Please compare code, ratings and approvals with the document before you place an order; see also the category listing.