Acoustic weight or mass sensing technology (referred to here as Acoustic
Weigh In Motion (AWIN)) provides accurate weighing of any type of moving
load moving over a load bearing medium. Acoustic transducers are affixed
to or embedded in the load bearing medium. One or more source acoustic
transducers propagate an acoustic wave over an acoustic path through the
medium between the source and receiver transducers when the medium is in
an unloaded state. The wave is detected at one or more receiving acoustic
transducers. A propagation time delay is determined for the unloaded
state. When a moving load travels over the acoustic path in the medium,
the acoustic propagation time delay for that loaded state is determined.
The difference between the acoustic propagation time delays for the
unloaded and loaded states is determined. That acoustic propagation time
delay difference is used to determine the weight or mass of the moving
load.