Abstract: An electrostatic shield for an electrical conductor element comprises a sheet-like array of closely spaced elongate electrical conductors interconnected at one end of the array by an end conductor for connection to a common or ground potential. The conductor to be shielded may be in the form of a loop or coil printed on one face of an insulating plate and the array of shielding conductors and the end conductor may be printed on the other face of the insulating plate. The shield may include two or more series of parallel conductors arranged in adjacent banks and each provided with a separate end connecting conductor.

Abstract: Method and apparatus for sorting objects according to the degree to which they possess a required characteristic. Objects are moved in a line on a conveyor belt past a line of detectors each responsive to the required characteristic. Each detector produces a time sequence of output signals and the signals from successive detectors are accumulated. The objects are projected from the downstream end of the conveyor belt in a free flight path past an optical scanner and a series of air blast nozzles. The scanner determines the portions and sizes of the objects and objects selected on a comparison of the detector signals and signals from the scanner are blasted with air jets from appropriate nozzles so as to be deflected from their free flight trajectory. Deflected and undeflected objects are caught in separate collection bins.

Abstract: In the photometric sorting of objects each object is examined in each of a predetermined number of zones for the presence or absence of one or more predetermined surface characteristics. The invention provides that a characteristic determined in one zone be attributed to at least one other zone into which the object extends.