In batch settling or flotation the velocity of the disperse phase u(d) = U(S)G(phi). U-S is the terminal velocity of an isolated particle, and G is the hindrance function. Vertical profiles of the fluid fraction in batch flotation experiments, measured by one-dimensional nuclear magnetic resonance (NMR) imaging, were input into a new method for extracting G. This simple, explicit calculation was tested on concentrated monodisperse and polydisperse samples. In a single experiment on a 44 mL sample of monodisperse suspension with overall solid fraction phi(i) = 0.2, the hindered flotation function G(phi) was measured over the range of 0.05 < phi < phi(m) where phi(m) is the maximum packing fraction. This represents significant simplification compared to observation of the clearing interface in a series of suspensions with varying phi(i). The hindrance function G was well fit by G(phi) = (1 - phi)(5) as expected for monodisperse samples. In a polydisperse suspension, the NMR hindrance function showed an initial transient, and thereafter was fit coarsely by G(phi) = (1 -phi)(4.4) in the range of phi(i) < phi < phi(m). The new procedure is useful for rapidly characterizing the settling or flotation of suspensions. Further, only a very small volume of suspension is required to measure G over a range of phi(i).