2. Experimental methods

With the application of zeroing methods, it is possible to compare resistances with each other and to determine the value of an unknown resistance, with great precision, when calibrated resistors are available. However, the high stability and accuracy of digital instruments also make it possible to carry out extremely precise measurements of the resistivity of samples, using elongation methods. In this case, the measurement of a resistor is reduced to a simultaneous measurement of the potential difference between its terminals and the current flowing through it. To measure the resistivity of solid or liquid metals, there are a large number of experimental devices based on this method, known as "with electrodes", as it requires the use of current supply and potential pick-up electrodes.

It is also possible to measure resistivity using certain physical laws or their...