An Expanded Scale Ohmmeter

Probably no instrument is used more than the laboratory ohmmeter. Perhaps because of the appearance of sensitive meter movements with large scales and the addition of electronic amplification, no instrument has seen less development in its basic design and none is more deserving of reappraisal. One of the basic defects in all existing ohmmeters is the scale-crowding which naturally occurs when a range of zero to infinity is adopted. This report describes a circuit modification which results in a considerable expansion of the ohmmeter scale, thereby making it possible to read resistance values more accurately.