Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An apparatus and method for detecting particles in a clean environment provides for forming a beam of electromagnetic radiation into an instantaneous scattering volume and scanning the scattering volume in space defined by a flow cell. Particles are transported by fluid means into the space occupied by the scattering volume and individual particles are multiply scanned while passing through the scanning scattering volume. A fluid conduit is provided to transport the fluid and the particles and windows are provided to transmit the radiation beam into the space defined by the flow cell and to transmit scattered radiation from the particles out of the space. The radiation from the particles is collected and detected to provide an output signal. In the preferred embodiment, the output signal is analyzed to determine the concentration of the particles in the fluid and to determine the size and velocity of each individual particle.

Abstract: The bushing balance controller is an electronic device which measures the voltage drop across each segment of a multiple segment glass fiber forming bushing and measures the current flow in the bushing. The device uses these measurements to produce error signals proportional to the difference in the set point temperature and the instantaneous temperature of each segment of the bushing. The device diverts current from each segment of the bushing whose error signal is greater than the average of the error signals for all segments of the bushing. The device also sums all error signals and passes this signal to a bushing controller which adds current to the bushing when the sum of the error signals falls below a preset value.

Abstract: The bushing temperature measurement device is a microprocessor based sensor which determines the temperature across a multi-segment electrical resistance heated glass fiber producing bushing. The temperature change is determined by calculating the change in resistance of each segment of the bushing by sensing the voltage drop across that segment and dividing by the current flowing in that segment. All measurements of voltage and current are taken simultaneously and averaged over several cycles. The microprocessor, through appropriate output circuitry, alerts other process controls to eliminate any change in temperature.

Abstract: A method and apparatus is disclosed for measuring the mass concentration of particulates entrained in a process or work area. One or more sensors are employed which electro-optically and continuously weigh the effluent extracted from the process area. The effluent is caused to enter a sample volume area either by convection or through a preseparator. The sampling volume is exposed to near infrared radiation of a light emitting diode (LED). An information signal indicative of small and large particulates entrained in the effluent is developed. The signal is converted and classified to signals corresponding to the presence of small or large particulates and further sub-classified as to size. The electro-optical "weighing" signals are operated on to produce a mass concentration read-out via an empirical algorithm exercised by a microprocessor in a centrally-located control/read-out unit which serves a multiple of remote sensors.

Abstract: A calibration/zero control is combined with an electro-optical measurement instrument in a time-multiplex fashion to provide a self-diagnostic in situ measurement system and automatic compensation of the entire electro-optical train without interruption of the measurement process. The electro-optical instrument includes a laser which provides a source of substantially monochromatic electromagnetic radiation (laser beam) and optics for collection and focusing radiation onto a detector. The radiation is directed through a sampling volume where it impinges upon an object whose properties or physical characteristics are to be measured by scattering techniques. The calibration/zero control includes an element rotatably positioned in the path of the electromagnetic radiation, optically upstream of the sampling volume, in having an axis of rotation perpendicular to the optical axis such that the radiation is periodically blocked and sampled.

Abstract: A method of and apparatus for monitoring the method comprising the steps of: generating electromagnetic radiation; using a first lens to form the electromagnetic radiation into a beam; directing the beam through a sampling volume for impingement upon the fibers; positioning a second lens in the same horizontal plane as the first lens such that the angle, whose tangent is D/d, is greater than or equal to five degrees, where D is the diameter of the second lens and d is the distance from a plane through the center of the second lens to the center of the sampling volume; collecting electromagnetic radiation backscattered from the fibers by means of the second lens; and generating a signal responsive to the amount of radiation collected as an indication of the average diameter of the fibers.

Abstract: A calibration/zero control is combined with an electro-optical measurement instrument in a time-multiplex fashion to provide a self-diagnostic in situ measurement system and automatic compensation of the entire electro-optical train without interruption of the measurement process. The electro-optical instrument includes a laser which provides a source of substantially monochromatic electromagnetic radiation (laser beam) and optics for collection and focusing radiation onto a detector. The radiation is directed through a sampling volume where it impinges upon an object whose properties or physical characteristics are to be measured by scattering techniques. The calibration/zero control includes an element rotatably positioned in the path of the electromagnetic radiation, optically upstream of the sampling volume, in having an axis of rotation perpendicular to the optical axis such that the radiation is periodically blocked and sampled.

Abstract: A system and method provides in situ measurements of the size of particulate matters suspended in fluid medium. A beam of intermittently interrupted electromagnetic radiation is directed through a portion of the fluid medium and radiation backscattered from a first optically defined region disposed within the fluid medium at a location having substantially uniform incident illumination is detected and utilized to provide an indication of the size and distribution of the suspended particles. To assist in assuring particles under surveillance are within the first region at the time the measurements are made, light backscattered from a further region disposed in the fluid medium and containing the first region is collected and compared with the intensity of the radiation backscattered from the first region prior to making the measurements.

Abstract: An improved system for accurately measuring temperature. The system is microprocessor based and automatically compensates for errors from such elements as cable resistance, drift and aging of the signal conditioning electronics. The system converts a non-linear electrical signal from a probe directly to a temperature indication in degrees Celcius. In the preferred embodiment, there is employed a multiplicity of probes and the system provides for automatically scanning of the probes and computation of the temperature for each.

Abstract: A system and method provides electro-optical in situ measurements of the mass per unit volume of particulate matter suspended in a fluid medium. A beam of electromagnetic radiation is directed through a portion of the medium and radiation back-scattered from an optically defined volume thereof is detected and utilized to provide an indication of the mass of the particles per unit volume of the medium. The beam is preferably a periodically interrupted beam of substantially monochromatic light having a wavelength of the order of magnitude of the mean diameter of the particles of interest. In one embodiment, the d.c. component of the detection signal is filtered out to eliminate the effect of any background radiation.

Abstract: 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.