Quadrupole mass spectrometer measurements of charged Octoil sprays, as displayed in Figure 1, reveal that operation in the emission limited regime is accurately represented by Z = exp(epsilon(0)/epsilon-r(s)/f), where: Z is the fraction of the emission limited charge level, epsilon(0)/epsilon the inverse relative dielectric constant of the spray fluid, r(s) the coupling parameter, and f is the inverse fine structure constant (137.04). The coupling parameter, (r(s)) defined as 1/(a(0)rootpin), where a(0) is the first Bohr radius, and n the surface charge density (m(-2)), is a non-dimensional measure of inter-charge spacing, and a fundamental descriptor of limited dimension (2-D) electron structures. This parameter implicates the physics of surface charge as the controlling element for emission limited electrostatic atomization. Moreover, this relationship forces the conclusion that the limiting emission electric field cannot be a constant.