A nano-ohm is a metric submultiple of the ohm, representing 10⁻⁹ ohms. Engineers use this tiny unit to measure the resistance of highly conductive materials, heavy busbars, and critical electrical joints where even minute resistance can cause significant power loss or heating at high currents. Specialized micro-ohmmeters or nano-ohmmeters are required to measure these values accurately.
Heard on the job
We measured the contact resistance across the main breaker terminals at just under fifty nano-ohms.
Insider tip
Measuring resistance in the nano-ohm range requires a four-wire Kelvin connection to eliminate the resistance of the test leads themselves.
Also heard as
- nΩ