Radio Frequency µSR provides a direct method for accurately determining muon hyperfine coupling constants, Aµ, for muoniated radical species. The method complements the well established Avoided Level Crossing and Transverse Field techniques, and can provide unique information in systems where the radical state is slowly formed. However, to get the best from the technique, development and benchmarking is needed. This proposal seeks to do this by measuring a well known system (acetone), but may also provide results beneficial to a parallel study of acetone (submitted to the present panel) where the aim is to develop and test computational methods for determining muon parameters.