Abstract: A device and method for detecting the nature and condition of ice, water or air on a surface by producing output signals by measurement of dynamic dielectric constant and electrical conductivity of the material on the surface and decoding digital signals therefrom to display information as to the condition. More particularly, a sensing apparatus for producing output voltage signals in response to the formation of ice, water or air at a surface and processing a combination of voltage levels as digital signals to decoding circuitry to provide information which is independent of contamination and impurities and of the size and nature of sensor elements.

Abstract: A device for estimating the number and the mass of particles borne in a fluid stream comprises a novel target on which the particles impact at a constant angle thereby generating acoustic signals proportional to the kinetic energy of the particles. The acoustic signals are converted by means of a transducer to corresponding electric signals which are processed by art computer means. Compensating probes are disclosed for subtracting extraneous noise.

Abstract: Detachable single and multiple keels for small boats are taught which are held in place by brackets and straps, the straps being secured to the boat above the waterline.