The old story of voltmeters needing infinitely high internal resistance and ammeters needing super low internal resistance. We can use meters with voltage and current to measure really low value resistors which can’t be measured with a DMM in the Ω range. A Wheatstone bridge with sufficiently high working voltage is handy but not everyone has this. So it comes down to using a pair of meters.
About 8 pages of graphics and text. 2MB download