Low-Resistance Measurement Techniques with an SMU

Measuring very low resistances requires careful control of both the stimulus and the measurement to avoid error from lead resistance, noise, and thermal effects. This video demonstrates the fundamentals of low-resistance measurement using a current-source approach and four-wire (Kelvin) connections to accurately capture small voltage drops across a device.

Using a 10 mΩ resistor as an example, the video shows how improper sensing introduces error, how remote sensing removes lead resistance, and how reducing source current can introduce noise and offset in DC measurements. It then demonstrates how switching to an AC (lock-in) technique improves stability and resolution, highlighting practical methods for reducing error when working with low-resistance, low-level signals.