Safearth CS3 milli-ohmmeter tester

The CS3 from Safearth is a purpose-built milli-ohmmeter for quickly and accurately testing in-service earthing systems.

Measuring the electrical continuity between elements of earthing and lightning protection systems is a necessary verification test or condition assessment for effective EMC management. The difference between an effective and ineffective connection could be as small as a few mΩ. A 1 kA fault (or strike) through a 10 mΩ joint results in 10 kW of heat, which could immediately destroy the connection, compromising EMC or causing other hazards. The milli-ohmmeter is specifically designed to identify these latent issues, ensuring accuracy in low resistance measurements across large distances in an online facility.

The instrument accurately measures the resistance between metallic structures in an installation and can be used to identify defects before they fail under fault conditions. It can measure multiple connections in a single test, while offering high AC and DC noise rejection. Other features include: wire resistance measurement; 0.1 mΩ to 10 Ω measurement range; 200 m maximum test lead length; 3 s typical measurement time; and >5000 measurements on a single charge.

The company says the device is capable of overcoming electrical noise while accurately measuring across large distances, providing reliable continuity measurements across the full extent of an in-service earthing system at an operating plant.