Abstract: High resolution in an X-ray computerized tomography (CT) inspection system is achieved by using a collimator/detector combination to limit the beam width of the X-ray beam incident on a detector element to the desired resolution width. In a detector such as a high pressure Xenon detector array, a narrow tapered collimator is provided above a wide detector element. The collimator slits have any desired width, as small as a few mils at the top, the slit width is easily controlled, and they are fabricated on standard machines. The slit length determines the slice thickness of the CT image.

Abstract: A simple, easily operated method and apparatus for determing the thickness and gas permeability of refractory coatings as such coatings are in place on foundry molds and cores. The apparatus is entirely portable, requires no connections to utility supplies such as electricity, air sources and so forth, and is hand-held during operation. The apparatus comprises a hand-held probe having an outlet orifice of known, predetermined size for making contact with the mold and a hand-held measuring unit which includes a cylinder having a gravity-actuated piston, a gas flow rate meter, and a gravity-actuated check valve. The two separate hand-held units are interconnected by flexible conduit. The cylinder and piston combination cause a flow of air at controlled pressure through the mold at the probe contact surface. In operation, the piston is actuated by inverting the hand held measuring unit and then reinverting to its normal position.