Eigenschaften
Range	4000 µΩ, 40 mΩ, 400 mΩ, 4000 mΩ, 40 Ω, 400 Ω
Dimensions / weight	270 x 250 x 180 mm / 5 kg
Test probe diameter	2 mm
Weight	2 x 420 g
Probe tip length	10 mm

The Chauvin Arnoux CA 6240 is a micro-ohmmeter for precise measurement of very low resistances in the range of 400 µΩ to 400 Ω. It is suitable for applications on-site, in workshops or in laboratories, where high accuracy and reliability of measurement results are required. The device operates using the 4-wire method, in which the resistances of the test leads and connections do not affect the measurement, ensuring high measurement accuracy. Measurement is performed with a maximum test current of 10 A, with different current levels (10 A, 1 A, 100 mA, 10 mA) used depending on the measurement range to optimise resolution and precision.

Applications

The CA 6240 is typically used for testing electrical connections, switchgear, cables, screw connections, earthing systems and other metallic conductors. The ability to measure resistances in the micro-ohm range makes it particularly suitable for diagnosing contact resistances, which are often the cause of increased current heating, sparking or failures. The robust design and protection rating IP53 allow use in industrial environments and outdoors, where dust and splashing water may occur.

Functions and Equipment in Detail

The device features an automatic measurement function that starts measurements without additional button pressing, simplifying operation for repeated measurements. Results can be stored in an internal memory for up to 100 measurement values, supporting documentation and later analysis. Test current reversal helps detect stray voltages and improve measurement accuracy. Maximum resolution is 0.1 µΩ, enabling detailed analysis of resistance changes. Measurement accuracy is 0.25 % ±2 pts across all ranges, ensuring high reliability of results.

Technology Explained Simply

The 4-wire measurement method, also known as Kelvin measurement, separates current supply from voltage measurement. This excludes the resistances of the test leads and connection points from the measurement. The CA 6240 uses special test probes with a probe diameter of 2 mm and a spacing of 3.5 mm. Cable length is 3.15 m, providing sufficient reach for many application scenarios. The test probes are designed for a maximum resistance capacity of 50 mΩ. Power supply is via a rechargeable NiMH battery, suitable for mobile use.

Compatibility and Accessories

Various accessories are available to extend functionality. These include optical USB cables for data transfer, mini-Kelvin clamps for 1 A, cables with Kelvin clamps for 10 A, a NiMH battery pack 6 V / 8.5 Ah, retractable and rotatable Kelvin test probes for 10 A, a power cable, and fuses (12.5 A, 500 V). A transport bag is also available for safe transportation of the device. Communication with a PC is via optical/USB connection, with software supporting monitoring and analysis of resistance values.

Installation and Mounting

Installation requires no special tools. The test probes are placed directly onto the contacts to be measured. The cable length of 3.15 m allows flexible positioning. The test probes are equipped with fork cable lugs (Ø 4–6 mm) and safety connectors (Ø 4 mm) to ensure a secure connection. Automatic shut-off ensures efficient battery usage.

Operational Advantages

The CA 6240 offers high measurement accuracy, simple operation and robust construction. Automatic functions reduce user effort, while memory storage and PC communication facilitate documentation and analysis of measurement results. The overvoltage category IEC 61010-1 CAT III 50 V ensures safe operation even in electrically demanding environments. The combination of mobile use, high precision and integrated safety features makes the device a reliable tool for professionals in electrical and measurement technology.

Note: Batteries are not included in the delivery scope.