An identification apparatus, capable of distinguishing between a first class of objects and a second class of objects. The transistor has a double diffused drain and a medium operation voltage such as 6 to 10 volts, which is advantageous for applications having both low and higher operation transistor devices. The difference between the first index of refraction and the second index of refraction is about 0. The object-side surface and the image-side surface of the second lens element are aspheric. The suction force is selected such that particles near the walls of the chamber tend to continue in a generally rotational and axially progressive path into a particle collecting regions of the chamber, while relatively particle-free air is drawn radially inwardly, as it progresses axially, so as to exit to a second separation stage, through the openings in the central member wall.