Abstract: An acoustic method for measuring the quantity and installed density of thal insulation includes introducing a sensing apparatus comprised of one or two acoustic transducers which are so placed as to measure the attenuation and/or phase shift of acoustic waves passing through the insulation. The thermal conductivity for a given insulation material may be monitored as a function of insulation depth by relating the acoustic amplitude and/or phase to a predetermined relationship for that particular insulation material. The relationship may be simply a set of tabular guides relating the quantity of insulation to an amplitude or phase value. This method may be applied to material in an enclosed space, an attic for example where remote access would be desirable, or to material in an open space.

Abstract: A bulb for a cathode tube comprising a cone having a narrow end adapted to receive electronic devices therein and a wide substantially rectangular base end having a screen with a curved viewing portion secured thereto. The curved viewing screen is provided with a substantially rectangular peripheral contour complementary to the contour of the base end of the cone and the viewing portion is so curved that the sections therethrough parallel to the cone base end define curves which are substantially parallel to the cone base and contour.