Low-Resistance Meter Circuit

The primary objective of the paper was to design a low-resistance meter that would further increase the accuracy and repeatability involved in the measurement of resistances as low as 0.1 Ω. The project embraced a Wheatstone Bridge with four-wire Kelvin sensing and rather sophisticated noise-reduction techniques in an attempt to minimize errors due to contact resistance, thermal EMF, and lead resistance. It was compared with standard digital multimeters, and significantly fewer errors in lowresistance measurements were obtained. Calibration and testing have been carried out that confirm higher accuracy and stability for the new meter. For future versions, efforts can go into automation and further noise reduction, focusing especially on industrial applications.