Chauvin Arnoux CA 6422 Earth Tester 2P/3P up to 2 kΩ

CA 6422 is a compact earth tester from Chauvin Arnoux for measuring the resistance of earth electrodes with two or three points, with a range up to 2 kΩ, a 600 V CAT IV rating and an IP 65 case.

A battery-powered earth tester for routine electrode checks

The 3P method uses two auxiliary rods, H and S, while the electrode under test acts as the third point. The CA 6422 injects a square-wave current of no more than 20 mA at 128 Hz or 256 Hz, which lets it reject the 50 and 60 Hz interference found near live installations. The 2P method is the quick alternative when an auxiliary rod cannot be driven.

A single TEST button starts the measurement in automatic mode. Three validation keys, 52 %, 62 % and 72 %, store readings taken with the S rod at those fractions of the electrode-to-H-rod distance, which is how the manual recommends confirming that the S rod sits outside the zone of influence of the electrode.

Features given in the manual

• Earth resistance 3P from 0.50 Ω to 2.000 kΩ in three ranges, with accuracy ±(1 % + 10 points) on the lowest range.
• Resistance measurement 2P from 0.05 Ω upward.
• Test frequency 128 Hz or 256 Hz to avoid interference.
• Voltage measurement UHE from 0.1 to 600.0 V, plus a NOISE indicator when a spurious voltage above 3 V is present.
• Warnings when the S rod resistance exceeds 50 kΩ or the H rod resistance exceeds 15 kΩ.
• Lead compensation that survives automatic switch-off but not power-off.
• Compliance with IEC 61557-1 and IEC 61557-5 for earth resistance.

Technical specification

Earth resistance (3P) ranges

Other measurements

General specification

CA 6422 and its sibling CA 6424

The manual covers the CA 6422 and the CA 6424. The CA 6424 adds ranges up to 50 kΩ, rod-resistance and current measurement, memory and rechargeable NiMH cells, whereas the CA 6422 is the simpler, AA-powered model limited to 2 kΩ. For typical building and lightning-protection electrodes, whose values are often far below 2 kΩ, the CA 6422 has enough range.

Using the 3P method

Plant the H and S rods in line with the electrode, with the S rod about 62 % of the distance between the electrode and the H rod. Pay the cables out fully and keep them apart to limit interference, then press TEST. To validate, store a reading at 62 %, move the S rod 10 % toward H and store another at 72 %, then 10 % toward the electrode for 52 %. If the three readings agree, the result is valid.

Repeat the measurement with the rods at a different distance or rotated by 90 degrees if you suspect earth currents or a groundwater vein. If the rods cannot be placed in a line, the manual allows a triangular layout. Keep rod cables away from power cables and metal pipes.

Applications in Oman and the GCC

Earth electrodes in sandy or rocky ground often have high and variable resistance, so electricians and inspectors check them at commissioning and at periodic inspections. Typical jobs include building earthing, lightning-protection down-conductors, telecom sites and solar array earthing. An IP 65 case is helpful when the instrument is carried across a dusty or wet site.

Accessories

The manual lists a carrying bag, a carrying handle, a four-point hands-free strap, a 15 m earth measurement kit, a 50 m expert earth kit and the G72 leakage-current clamp. See other instruments in the Portable Test & Measurement category.

Selection and installation notes

Electrical test instruments are selected from the test voltage or current, the range and the safety category. Check the leads and the instrument before each use, make sure the circuit is isolated and proved dead before a resistance or insulation test, discharge the test object after an insulation test, follow the site safe-working procedure and keep the calibration current according to your quality system. Record the test conditions with each result.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Frequently asked questions

What is the highest earth resistance the CA 6422 can show?

Its 3P range tops out at 2.000 kΩ.

What batteries does it use?

Six LR6 (AA) batteries. The NiMH version with a charger is the CA 6424.

Are earth rods supplied?

No. The delivery is the instrument, batteries and a getting-started guide; rod kits are listed as accessories.

What do the 52 %, 62 % and 72 % keys do?

They store readings with the S rod at those positions so you can confirm the rods lie outside the electrode zone of influence.

Does Seven Star LLC act as a Chauvin Arnoux distributor?

No. Seven Star LLC is an independent supplier in Muscat that sources Chauvin Arnoux products on request.

Documents and quotation

This page carries the official Chauvin Arnoux user manual for CA 6422. Seven Star LLC is an independent supplier in Muscat and sources Chauvin Arnoux products on request; tell us the quantity and delivery point to receive a quotation. Always confirm the order code and technical values in the document first. See more in the product category.