Ohmmeters

An ohmmeter is an instrument used to measure electrical resistance and verify the continuity of circuits and components. Models range from general-purpose digital units suited for everyday electrical testing to precision micro-ohmmeters designed for milliohm- and microohm-level measurement in demanding industrial environments. Accuracy, resolution and test current vary by instrument type, making it important to specify the right tool before purchase. RS Hong Kong stocks a broad selection across portable, benchtop and industrial configurations, covering maintenance, production and laboratory applications. Browse the range to find the right instrument for your testing needs.

Types of Ohmmeters

Ohmmeters are available in several distinct configurations, each optimised for a different measurement range, accuracy requirement or working environment.

General-Purpose Digital Ohmmeters

General-purpose digital ohmmeters cover the resistance measurement ranges needed for routine electrical and electronic testing. These instruments check component values, verify wiring continuity, identify open or short circuits and support basic fault-finding on electrical panels and assemblies. Most offer multiple resistance ranges with clear digital displays, making them a practical everyday tool for electricians, technicians and workshop environments.

Low-Resistance Ohmmeters

A low-resistance ohmmeter is designed to measure resistance values in the milliohm range, where a standard instrument would lack the resolution to return a meaningful reading. It is the appropriate choice for testing cable joints, busbar connections, switchgear contacts and bonding conductors, where even small amounts of excess resistance can cause overheating or voltage drop under load. These instruments typically use a four-wire Kelvin measurement technique to eliminate test lead resistance from the reading.

Micro-Ohmmeters

A micro-ohmmeter extends precision resistance measurement into the microohm range for applications where the highest level of accuracy is required. These instruments are specified for transformer windings, motor armature resistance, circuit breaker contacts and precision electrical components where differences in the microohm range are diagnostically significant. They are a standard tool in power engineering, substation maintenance and high-precision manufacturing environments.

Portable / Handheld Ohmmeters

A handheld ohmmeter is designed for field service, site maintenance and on-equipment testing where portability is the priority. Compact and battery-operated, these instruments allow resistance and continuity checks to be carried out away from the bench, making them well suited to maintenance technicians and field engineers working across multiple sites or in confined installation environments.

Typical Applications for Ohmmeters

Resistance measurement is a core diagnostic and quality assurance task across a wide range of industries. The following represent the most common professional contexts where ohmmeters are used:

• Electrical Testing & Maintenance: Electricians and maintenance engineers use ohmmeters to verify contact resistance in switchgear, motor terminations and distribution board connections. A low-resistance ohmmeter is particularly valuable here, detecting degraded joints and loose connections before they cause overheating or equipment failure. Continuity verification across protective earth conductors and bonding paths is also a standard application during installation testing and periodic inspection.
• Electronics Manufacturing: In electronics production environments, ohmmeters are used for quality control testing of PCB traces, solder joints, connector terminations and passive components. Precise resistance measurements at this stage help identify dry joints, open circuits and out-of-tolerance components before assemblies move further along the production line, reducing rework costs and improving product reliability.
• Power Generation & Distribution: Power engineers and substation technicians rely on micro-ohmmeters and low-resistance ohmmeters to test transformer winding resistance, circuit breaker contact resistance and busbar connection integrity. Accurate resistance data at this level supports both routine condition monitoring programmes and fault investigations, helping to maintain the reliability of high-voltage distribution infrastructure.

Buy Ohmmeters Online from RS Hong Kong

RS Hong Kong is a trusted ohmmeter supplier stocking instruments from leading brands including RS PRO, Megger, and Extech, covering general-purpose, low-resistance, micro- and handheld configurations across a wide range of accuracy and measurement specifications. Complementary products including LCR meters and ESD testers are also available to support a complete electronic component testing setup. For full details on delivery services and charges, please visit our Delivery Information page.