The viscoelastic theory for ripples at a liquid-air interface has been sketched. It includes corrections for any gravity effects. The electronic instrumentation has been modified to include frequencies below 200 cps. The weight of the ripple generator is an important factor to consider as it should be heavier for the lower frequencies and lighter for the higher ones.
Grossman, Stuart C. and Hansen, R. S., "Propagation characteristics of capillary ripples on solutions of low molecular-weight organic acids" (1964). Ames Laboratory Technical Reports. 65.