Does radar work on foam?
The effects of foam on a radar measurement can be difficult to predict. In some applications the foam may dampen out the signal completely while other types of foam may be transparent to the transmitter. The thickness, density and the dielectric constant are factors that need to be considered when evaluating an application with foam. On dry foam the microwaves typically passes through and detects the liquid surface below. On medium type foam the signal can be absorbed or scattered and the results are therefore hard to predict. If the foam is wet the microwaves are often reflected from the foam surface and thereby the foam surface level is measured. The frequency at which the radar operates also affects how foam is measured. Low frequency radar (5 GHz) in general penetrates foam to a larger extent than high frequency (20 GHz) radar. Guided Wave Radar is in general better suited to measure on applications where foam is present since the radar uses a lower frequency pulse.
