Electrical Resistance Testing Solutions

Identify Hidden Faults with Micro-Ohm Precision

Loose connections cause overheating and failure. Our digital low resistance ohmmeters deliver the high test currents needed to verify bond integrity, helping you maintain a stable and efficient electrical infrastructure across your entire network.

Get a quote

Eliminate Risks in High Voltage Environments

We design our ohmmeters to protect operators from dangerous induced voltages. By verifying grounding systems and lightning protection, we help you secure your facility against hazardous electrical events and prevent catastrophic equipment damage.

Dependable Results in the Harshest Field Conditions

Electrical noise and rough environments compromise ordinary testers. Our rugged instruments filter out interference to provide stable, repeatable readings, ensuring you get accurate data to track asset degradation over long operational periods.

Optimise Asset Health with Actionable Data

Don’t just measure resistance; understand the trend. Our tools allow you to store and analyse results, transforming raw numbers into clear indicators of joint health. This enables predictive maintenance strategies that prevent unplanned outages.

Ground Testing and Earth Resistance Testers

Find out more

Megger low resistance ohmmeter used for low resistance testing in outdoor field conditions.

Low Resistance Testing Solutions

Find out more

Trusted accuracy in real-world conditions

Resistance measurements must be accurate, even when testing in harsh or electrically noisy environments. Megger instruments use true four-terminal (Kelvin) measurement techniques to eliminate the effects of test lead and contact resistance. Combined with high-output test currents, bi-directional testing, and advanced filtering, our solutions deliver stable, repeatable results you can rely on for diagnostics, commissioning, and trending.

Built for the field

Electrical testing doesn’t happen in perfect conditions. Our DLRO and MOM instruments are designed for tough, real-world environments—from substations and switchyards to rail infrastructure and industrial maintenance sites. Rugged housings, high ingress protection ratings, and optional heavy-duty models ensure dependable operation in poor weather, confined spaces, and demanding schedules, such as overnight maintenance windows.

Reduce downtime and energy loss

High resistance at joints and connections can cause excessive heating, energy loss, voltage drops, and even fire risk. Megger’s resistance testers help you detect these issues early, improving the efficiency and reliability of electrical systems. Identifying and correcting high-resistance faults prevents failures, reduces operational energy waste, and supports carbon-reduction goals.

Proven insight for critical applications

From substation busbars and transformer connections to rail bonding and UPS systems, Megger has deep expertise across every sector of power and transportation infrastructure. Our instruments support both routine testing and advanced diagnostics—helping operators comply with standards, protect personnel, and maintain dependable network performance.

Frequently asked questions

What is electrical resistance testing used for?

It verifies the integrity of electrical joints, conductors, grounding systems, and contact interfaces. Measuring resistance helps detect issues such as corrosion, loosening, contamination, and mechanical degradation that can lead to overheating, power loss, or failure.

Which instrument should I use for circuit breaker contact resistance testing?

Circuit breakers typically require high-current, four-terminal testing. Models such as the MOM2, MOM600A, or DLRO100 provide the high test currents and clamp options needed to obtain reliable contact resistance measurements, even with limited access.

Why is resistance testing important in rail systems?

Low resistance ensures effective bonding, lightning protection, signalling continuity, and safe fault return paths. Routine testing helps prevent step/touch voltage hazards, overheating at joints, and service disruptions.

What test current should I use?

Use the highest test current permitted by the equipment under test. Higher current helps overcome thermal EMF effects, contamination, and surface oxidation, producing more accurate and repeatable results.