Venturedyne, Ltd.

Gerhard Kreikebaum

David L Chandler

Justin F Dean

Edward F Patterson

Raymond J Felbinger

Scott M Dick

A portable microbial gaseous-fluid sampler includes a gaseous-fluid flow system at least partially supported by a structure. The gaseous-fluid flow system includes a gaseous-fluid intake portion having an intake port, a blower in fluid communication with the intake port, and a gaseous-fluid exhaust portion having an exhaust port. The sampler can further include an exhaust filter operable to substantially filter a totality of the gaseous fluid flowing through the sampler prior to exhausting the gaseous fluid. The sampler also can include a control system operable to control at least gaseous-fluid flow through the sampler, and a remote sampling head.

Microbial gaseous-fluid sampler and method of operating the same

Disclosed is a particle sensor having a light beam with a beam long axis and an air flow tube with an inlet end and a particle exit mouth. In an aspect of the invention, the cross-sectional area of the flow passage at the inlet end is greater than the cross-sectional area of the exit mouth. This enlarged area dramatically reduces pressure drop along the tube. The exit mouth is in registry with the light beam and is elongate in a direction substantially parallel to the beam long axis. Thus, particles flowing through the mouth pass through the beam. In another aspect, the invention includes a centrifugal blower which is light in weight and which may be battery powered.

Particle sensor with variable-speed blower

A particle sensor operates in ambient air at an ambient air temperature and includes (a) a light source projecting a beam of light, (b) a light trap aligned with the beam of light and comprising at least one light-energy-absorbing surface at a surface temperature, (c) a nozzle flowing particle-entraining air through the beam of light, and (d) an opto-electrical system detecting light scattered by a particle. In the improvement, the sensor includes a cooling apparatus in heat transfer relationship to the surface and absorbing heat from such surface. The surface temperature is maintained at or below a value which substantially eliminates thermally-induced electro-optical disturbances in the sensor. A new method for reducing electrical noise detected by an opto-electrical system in the particle sensor includes providing a cooling apparatus in heat transfer relationship to the surface and transferring heat from the surface to the cooling apparatus at a rate which limits the surface temperature to a value which substantially eliminates thermally-induced electro-optical disturbances in the sensor.

Particle sensor with cooled light trap and related method

The new particle sensor is used for assaying particles and includes a light source comprising one or a plurality of light-emitting laser diodes. Light from each diode propagates along a flexible conduit or 'light pipe,' preferably a separate fiber optic strand. The sensor has a low voltage power supply and drives the diodes at 1-5 VDC. Light from one or bundled fiber optic strand(s) is focused by a focusing lens to provide an intense light beam for small-particle detection. For improved design flexibility, the light source may be mounted independently of the light beam long axis.

Particle sensor with fiber optic conductor

Particle sensor with low-pressure-drop air flow system

The disclosure involves a particle sensor having a mirror cavity unobstructed by masks and the like. A light detector is at the mirror secondary focal point and well outside the mirror cavity. A variation includes a beam splitter and a secondary light detector to improve detection of larger particles. A second embodiment includes a pair of elliptical mirrors offset along the light beam. Light reflected by the second mirror represents only changes in laser power and light scattered by gas molecules. The resulting signal is subtracted from that produced by the first mirror to obtain a relatively 'clean' signal useful to assay very small particles.

Improved particle sensor and method for assaying a particle

The liquid nephelometer has an elongate, tubular housing for containing a liquid sample to be measured for the concentration of foreign materials, a light source located adjacent one or both ends of the housing for directing a beam of light along an axial path through the housing, a light restrictor having a aperture of reduced cross sectional area to divide the interior of the housing into a first or sensing chamber having a known volume and a second chamber and to limit the passage of the scattered light between the two chambers, and light detecting means for detecting light scattered by foreign material in the liquid present in one or both of the chambers and producing a signal representative of the concentration of such foreign material. In a preferred embodiment, the light source is located at the end of the housing including the sensing chamber, the portion of the housing including the second chamber is made from or coated with a light absorbing material and the light detector is disposed between the light source and the end of the sensing chamber, has a central opening through which the light beam passes and detects light back scattered by foreign material present in the liquid in the sensing chamber.

Growing community of inventors

San Bernardino, CA, United States of America

Gerhard Kreikebaum