His or her expectation is that the voltage drop across the resistor reflects the precise current passing through it. 1b, i.e. a series connection of the resistors becomes effective. Sense resistors however, are mostly in the very low ohm range, for example 10m W . The equivalent circuit of a four-pole resistor is shown in fig.
Noise voltage is independent of the individual resistor construction and material.
From theoretical consideration., it is easily deducted that noise voltage is a function of temperature, frequency, and especially of the square root of resistance. Superinposing the voltage drop across the resistor this mostly will be negligible but should be known well. The frequency response of the configurations according to fig. 2a and fig. 2b is easily calculated and shown in fig.