Abstract: A specimen holder has flexible walls to provide good electrical contact between a material to be tested for its electrical properties and the conductors of a coaxial cable. The walls of the specimen holder are tubular in shape and coaxial and have a plurality of longitudinal slots spaced therearound to provide strips which are flexible in the radial direction. The walls are permanently distorted in a radial direction to urge them towards each other and into spring-like contact with an annular material specimen inserted between them. The specimen holder is particularly suited for measuring the electromagnetic shielding effectiveness of materials.

Abstract: A digitizer comprising electromechanical and optical components arranged to provide a precision metrology aid for sensing, displaying, recording, and ultimately "playing back" the coordinate values of selected features or locations of all or parts of two dimensional contours taken from drawings, pictures, and other two dimensional media. Data pertaining to a third dimension may also be entered into the digitizer. Precision is achieved from a combination of factors including the inherent rigidness of the structure, built-in mechanical force control, and the inclusion of apparatus for the elimination of input vantage point parallex.