Found on Eoin O'Riain's Readout blog:
http://instrumentsignpost.wordpress.com/2010/08/12/level-detection-of-foaming-media/
It seems that the Swiss/Danish instrumentation company Baumer Group has resurrected the radar point level switch application first produced in the early 1990s by the CannonBear group within TN Technologies (now a Thermo product group). The CannonBear implementation, as is the Baumer one, was extremely sensitive to changes in the dielectric of materials, and was very difficult to get to sense an accurate point level in the presence of foam or other interfaces.
The Baumer device appears to be designed for foam/liquid interfaces, and it will be extremely interesting to see how well it works. The press release quoted on the Instrumentation SignPost blog indicates a number of sanitary applications in the dairy industry.
Keep watching this, because I've always felt the technology was cool, and should work.
