FIG.24 Root-mean-square amplitude δg of the conductance fluctuations (in units of e2/h) as a function of the ratio of the distance between the voltage probes L to the estimated phase coherence length l_ for a set of Si inversion layer channels under widely varying experimental conditions. The solid and dashed lines demonstrate the (L/l_)−3/2 and (L/l_)−2 scaling of δg in the regimes L > l_ and L < l_, respectively. Taken from W. J. Skocpol, Physica Scripta T19, 95 (1987).