Thin targets of Sb, Te, Ho, Ta, W, Pt and Bi have been employed and L X-ray yields have been measured as a function of proton energy from 1.5 to 3.8 MeV. From these measurements the individual and total X-ray production cross sections and their ratios have been calculated and compared with the experimental results reported by other authors and with the perturbed stationary-state plane-wave Born approximation with correction for Coulomb deflection, relativistic and energy-loss effects resulting in the ECPSSR theory of Brandt and Lapicki (1979, 1981).