Fluid monitoring methods, sensors and systems are disclosed. Preferred embodiments comprise two or more mechanical resonators, preferably two or more flexural resonators configured for sensing, monitoring or evaluating one or more fluids at multiple positions within one or more fluidic systems. In the methods, sensors and systems of the invention, signals generated in response to stimulation of the mechanical resonators are communicated by multiplexing over a common communication path, and then deconvoluted with respect to the position of the resonators.