Abstract: A mixer for analytical application mixes a container of fluid without a magnetic stir bar. A device for testing a liquid for particles can use the mixer. The mixing can occur in a sealed container, and liquid can be transmitted to the device from the sealed container.

Abstract: Fluid-based particle detection exhibits improved light collection and image quality from a light collection system that uses immersed optics on a flow-through cell for collecting and detecting scattered light from particles carried by the fluid.

Abstract: Disclosed are light extinction-type optical particle detection systems and methods for their use. One such system comprises a laser source that produces a laser beam. The laser beam propagates from the laser source in response to a drive current having an amplitude that reaches a lasing threshold. The laser beam is characterized by mode-hopping noise energy that is produced by spurious switching of laser operating modes. The system also comprises a view volume through which the laser beam propagates and a stream of target particles immersed in a carrier fluid flows. The system also comprises a light-extinction type detector positioned on a side of the view volume opposite of the laser source. The laser beam strikes the target particles and thereby affects an amount of the laser beam that is incident on the detector, which produces, in response to the incident laser beam, a detection signal corresponding to a number of target particles in the view volume.

Abstract: A particle detection system exhibits an increased ability to detect the presence of submicron diameter particles and to distinguish between noise and pulse output signals generated by small diameter particles on which a light beam is incident. This increased ability results from the incorporation of a light reflector, a pair of detector elements that detect correlated portions of the light beam that have been scattered in multiple directions, and a coincidence circuit that determines whether each detector element in the pair concurrently generates a pulse output signal exceeding a predetermined threshold. Sample particles are counted only when both detector elements concurrently detect scattered light components.