摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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. The laser source is synchronously pulsed to fire in accordance with the position of the calibration/zero element. The calibration/zero element is constructed such that in one blocking position, a predetermined fraction of the laser beam is allowed to penetrate and pass through the element to the collection optics and detector. The analog voltage of the detector is time-multiplexed to develop diagnostic information including a calibration signal, a zero radiation signal and a measurement signal. All signals are developed under the control of a timing signal derived from the calibration/zero control.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.