J. Yannone
Microbridge

This paper discusses how to measure resistance in the range of 0.001 to 10 ohm, in 0.001-ohm increments, with a relatively low-cost design. Key to the project is use of Rejustors to allow use of lower-cost components which are then trimmed to higher precision, including the voltage reference, voltage-to-current (V/I) converter, and difference amplifier.