Hach Ultra Analytics, Inc.

Pacific Scientific Instruments Company

James Brady

Kenneth L Girvin

Richard K DeFreez

Geoffrey Wilson

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. The flow-through cell includes first and second body sections that are coupled to form a unitary article and have opposed interior surface portions configured to form opposed walls of a flow channel through which the fluid flows. First and second optical elements are associated with the respective first and second body sections. In certain embodiments, at least one of the first and second optical elements is an integral part of its associated body section. A lens element constructed as an integral part of the unitary flow-through cell eliminates additional interfaces or bonding joints that cause scattering and absorption of light.

Particle detection system implemented with an immersed optical system

A method for statistically distinguishing between two or more populations, such as between samples containing background and threat particles, is disclosed. According to one embodiment, the method for statistically distinguishing is a method for processing a signal in a particle detection system. The method may include characterizing each particle detected by a signal vector. The method may further include calculating a weight of each particle detected using a weighting function of the signal vectors. The weighting function may be a functional of a threat particle probability distribution and a background particle probability distribution. The method may also include summing a total weight of all particles tested and generating an alarm signal if the total weight exceeds an alarm level.

Methods and systems for signal processing in particle detection systems

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.

Growing community of inventors

Ashland, OR, United States of America

James Brady