Abstract: A particle concentrator, having a top and a bottom and including a hollow outer hub, having a top and bottom and bottom wall, and a side wall defining a plurality of sampled airflow inlet slots. An inner hub is placed in the outer hub and has a hollow interior, and which for each one of the sampled airflow inlet slots, supports a blade defining a secondary airflow slot aligned to a sampled airflow inlet slot, is sealed at its top, and is in fluid communication with the hollow interior of the inner hub, and wherein each adjacent two blades define a space between blades. A fan assembly is for blowing air out of the top of the outer hub, from the spaces between blades, causing air inflow through the sampled airflow inlet slots, some air then flowing into the secondary airflow slots, where it flows into the inner hub.

Abstract: A concentrator, wherein the concentrator comprises an air processor that includes a sampled airflow inlet slot that receives a sampled airflow that contains particles containing target material. A secondary airflow inlet slot that is located downstream from the sampled airflow inlet slot. The sampled airflow inlet slot uses centrifugal force to concentrate particles containing target material into a central portion of the sampled airflow, and produces a non-collimated sampled airflow. The secondary airflow inlet slot is operable to divide a secondary airflow from at least a part of the central portion of the sampled airflow that is received by the secondary airflow inlet slot from the sampled airflow inlet slot, and is operable to divide side primary airflows from the non-collimated sampled airflow produced by the sampled airflow inlet slot. Finally, the secondary airflow flows through the secondary airflow inlet slot.

Abstract: A concentrator, wherein the concentrator comprises an air processor that includes a sampled airflow inlet slot that receives a sampled airflow that contains particles containing target material. A secondary airflow inlet slot that is located downstream from the sampled airflow inlet slot. The sampled airflow inlet slot uses centrifugal force to concentrate particles containing target material into a central portion of the sampled airflow, and produces a non-collimated sampled airflow. The secondary airflow inlet slot is operable to divide a secondary airflow from at least a part of the central portion of the sampled airflow that is received by the secondary airflow inlet slot from the sampled airflow inlet slot, and is operable to divide side primary airflows from the non-collimated sampled airflow produced by the sampled airflow inlet slot. Finally, the secondary airflow flows through the secondary airflow inlet slot.

Abstract: A concentrator that is operable to concentrate particles of target material from a high flow rate sampled airflow into a low flow rate secondary airflow. The concentrator may have an array of radially arranged blades. Each blade may have a sampled airflow inlet that uses centrifugal force to concentrate the particles into a central portion of the sampled airflow passing through it. Downstream, the blade may also have primary airflow outlets and knife-edged secondary airflow inlets that divide the sampled airflow into a pair of lateral, high flow rate primary airflows from which the particles have been depleted, and a central, low flow rate secondary airflow which carries the concentrated particles.

Abstract: A concentrator that is operable to concentrate particles of target material from a high flow rate sampled airflow into a low flow rate secondary airflow. The concentrator may have an array of radially arranged blades. Each blade may have a sampled airflow inlet that uses centrifugal force to concentrate the particles into a central portion of the sampled airflow passing through it. Downstream, the blade may also have primary airflow outlets and knife-edged secondary airflow inlets that divide the sampled airflow into a pair of lateral, high flow rate primary airflows from which the particles have been depleted, and a central, low flow rate secondary airflow which carries the concentrated particles.

Abstract: An optical assay apparatus is described which includes a light source module and an optical sensing element coupled by an interrogation module. The light source module produces light having propagation angles ranging from a lower, non-zero limit. This is accomplished by including an obscuration which blocks low propagation angle light. The sensing element includes a reflector portion and an sensing fiber portion. The reflector portion receives, as incident light, the light produced by the light source module and produces, as reflected light, light having an approximately constant propagation angle, preferably just less than the critical angle of the sensing fiber. The sensing element also includes a lens position which collimates signal recovery light collected by the sensing fiber. The interrogation module includes a window containing a light source optical fiber that transmits light from the light source module to the sensing element.