Abstract: A wide range particle counter has sections which separately detect coarse and fine particles in an aerosol. The coarse particles are counted and sized in an optical particle counter. The fine particles are classified with a differential mobility analyzer to determine size and then passed through a vaporizer and condenser and also counted. Using the different sections permits counting and measuring a wide range of particle size in a single instrument with high accuracy and reliability.

Abstract: Examinations of biological, biochemical, and chemical characteristics of media, mainly of biologic origin, or media that are in contact with biological objects whose living is influenced by the media characteristics. One excites surface plasmon polaritons on a metal layer covered with a material sensitive to the examined characteristics of a medium, produces an interference with a beam of radiation reflected under these conditions and a reference beam, records parameters of a spatial intensity distribution in the resulting interference pattern, and judges the examined characteristics on the basis of the recorded parameters. The proposed method and apparatus ensure the technical result that consists in upgrading of sensitivity and resolution of measurements, at least, by two orders.

Abstract: In accordance with the present invention a projectile sensor comprises a support means, a lens means and a photocell comprised of multiple parallel photosensitive elements interposed by one or more diagonal photosensitive elements on or of a substrate disposed so as to provide changes in their electrical response when objects passing linearly through the sensor's field of view form an image through a lens upon the photosensitive elements in sequence. In its simplest embodiment, the photosensitive elements of the sensor substantially form a forward or reversed English letter “N” shape, such that a projectile's image passing over the photosensitive elements produces a series of electrical responses, where the ratios of the times between such changes relate to the velocity and position of the object.

Abstract: A ferrographic apparatus and method incorporate a priming operation that moves a priming fluid, in a direction opposite to the flow direction subsequently followed by the sample fluid, through a fluid pathway including the flow chamber. The fluid pathway is configured to facilitate dissipation of any gas bubble introduced into it during the priming operation and to reduce adventitious deposition of specimen material at locations other than the substrate. Sample fluid to be analyzed is added to the reservoir so as to form a bubble-free interface with the priming fluid, and the direction of movement through the flow chamber is reversed. The resulting continuous fluid column is advanced through the fluid pathway so that the sample fluid enters the flow chamber through the inlet port and passes through the magnetic field gradient, exiting through an orifice at the opposite end of the flow chamber serving as the outlet port.

Abstract: The method described comprises the following steps: measuring, with a spectroscopic ellipsometer, the values of two quantities which are dependent on the thickness of the altered silicon layer and of a thin layer of silicon dioxide grown thereon with variations in the wavelength of the light of the measurement beam of the ellipsometer, obtaining from these measured values respective experimental curves representing the two quantities as functions of the wavelength, calculating the theoretical curves of the two quantities as functions of the wavelength considering the refractive indices and absorption coefficients of silicon dioxide and of the altered silicon as known parameters and the thickness of the altered silicon layer and the thickness of the thin silicon dioxide layer as unknowns, comparing the theoretical curves with the respective experimental curves in order to determine for which values of the unknowns the curves under comparison approximate to one another best, and extracting from the values dete

Abstract: An opposed-flow virtual cyclone for aerosol collation which can accurately collect, classify, and concentrate (enrich) particles in a specific size range. The opposed-flow virtual cyclone is a variation on the virtual cyclone and has its inherent advantages (no-impact particle separation in a simple geometry), while providing a more robust design for concentrating particles in a flow-through type system. The opposed-flow virtual cyclone consists of two geometrically similar virtual cyclones arranged such that their inlet jets are inwardly directed and symmetrically opposed relative to a plane of symmetry located between the two inlet slits. A top plate bounds both jets on the "top" side of the inlets, while the other or lower wall curves "down" and away from each inlet jet. Each inlet jet will follow the adjacent lower wall as it turns away, and that particles will be transferred away from the wall and towards the symmetry plane by centrifugal action.

Abstract: A ferrographic apparatus and method incorporate a priming operation that moves a priming fluid, in a direction opposite to the flow direction subsequently followed by the sample fluid, through a fluid pathway including the flow chamber. The fluid pathway is configured to facilitate dissipation of any gas bubble introduced into it during the priming operation and to reduce adventitious deposition of specimen material at locations other than the substrate. Sample fluid to be analyzed is added to the reservoir so as to form a bubble-free interface with the priming fluid, and the direction of movement through the flow chamber is reversed. The resulting continuous fluid column is advanced through the fluid pathway so that the sample fluid enters the flow chamber through the inlet port and passes through the magnetic field gradient, exiting through an orifice at the opposite end of the flow chamber serving as the outlet port.

Abstract: A vapor sample detection method where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample.

Abstract: A method and apparatus for detecting impurities in quartz sand. The apparatus comprises at least one light source; at least one light detector assembly; a transport device; and a signal processor that receives the at least one signal from the at least one light detector assembly. The method comprises moving the quartz sand; illuminating the quartz sand to excite luminescence emission from impurities; receiving luminescence emission from the impurity; generating at least one signal indicative of the excited luminescence emission from the impurity; and determining if the signal represents an impurity in quartz sand.

Abstract: A system for detecting the presence of contaminants in a flowing stream of supercritical fluid. A sample stream is removed from a flowing stream of supercritical fluid and subjected to reduced pressure in a contaminant measurement zone. The supercritical fluid turns into gas at the reduced pressure with the contaminants remaining in a non-gaseous form. An attenuated total reflectance plate is used to spectrophotometrically detect the presence of the non-gaseous contaminants which deposit on the surface of the plate within the contaminant measurement zone. The system is useful for spectrophotometrically detecting the presence and identity of contaminants in supercritical fluids and is useful in monitoring both cleaning processes and extraction processes.

Abstract: Measuring chamber for flow cytometer for the measuring of fluorescent and scattered light of individual cells or other microscopic particles, comprising: a body (2) with a flat surface (6), an inlet chamber (8) and an outlet chamber (10) within the body (2), which open on the surface (6), the chambers being positioned one in front of the other and being connected by a channel (12), the chamber (8) being equipped with an inlet tube (14) and an injection tube (16) and the chamber (10) being equipped with an outlet tube (18), a transparent plate (20) placed in front of the surface (6), and moveable from a first position detached from the surface to a second position in which the plate closes to seal the chambers (8, 10) and the channel (12), with optical means placed in front of the plate to direct light on a particle placed in the channel (12) and to receive fluorescent light emitted from the same particle, characterized by the fact that the axis of the tube (16) intersects the optical axis (30) of the optical

Abstract: An apparatus and a method to remove and collect ferrous particles from a fluid for ferrous particle analysis. In one embodiment, the apparatus includes a holder chamber and a removable examination slide within the chamber. A magnet induces a magnetic field at the examination slide. A portion of the fluid is passed over the slide in order for the magnetic field to retain ferrous particles on the slide. Thereafter, the slide can be removed from the holder chamber for ferrographic analysis.

Abstract: A method of providing particle deposition on a semiconductor wafer or other surface first provides a flow of clean gas into a deposition chamber that purges the chamber prior to introduction of the wafer, and after introduction, continues the flow of clean gas. An aerosol is mixed into the clean gas flow for a desired length of time, so that as the combined flow passes through the deposition chamber particles are deposited on the wafer supported in the chamber. After the deposition has continued for either a desired particle count or a length of time, the flow of aerosol is discontinued, and a clean gas flow sheath is provided over the wafer as it is removed from the chamber. The apparatus carries out this method by providing a source of a clean gas, valves for controlling aerosol introduction into the clean gas, and a support for the wafer in the path of gas introduced into the chamber.

Abstract: A device for collecting a specimen, including (a) a test vessel for containing a solution containing an immunocomplex, which is a complex as a result of an antigen-antibody reaction between a specimen and a magnetic-labeled antibody containing a magnetic micro-particle and an antibody fixed to the micro-particle, (b) an external magnetic field generating device for generating a magnetic field, preferably a gradient magnetic field and applying it to the solution in the test vessel to effect local concentration of the immunocomplex to a predetermined position, (c) a magnetic member for collecting the immunocomplex at the position of local concentration, and (d) a moving mechanism for achieving relative movement between the magnetic member and the test vessel.

Abstract: In a stained particle analyzing method and apparatus for staining a test sample containing suspended particles, shooting an image of the stained sample, and classifying the particles and computing the density from the shot image of the sample, the sample, which may not be analyzed precisely, is detected before the start of an image analyzing process. Only the sample, which will be analyzed precisely, is stained and subjected to the image analysis. Color information of the sample before the staining is detected and stored. Color information of an image of the sample shot after the staining is compensated based on the color information of the sample detected before the staining. The sort and density of the particles are classified and computed on the basis of the image after the color compensation.

Abstract: The present invention is an apparatus for detecting iron based particulate matter in air/gas streams. The sensor 10 includes a flow through sensor body 11 having an interior surface. A high power magnet 12 for use in attracting airborne iron particulate matter is formed as part 13 of the interior surface of the sensor body. A high contrast photoelectric sensor 14 coupled to a fiber optic bundle 15 is used for detecting changes in the contrast of the magnetic surface.

Abstract: A fuel contamination detection system for use in testing the contamination level of a fuel sample, wherein the system is selectively operable in a first mode as a particulate detector and in a second mode as a free water detector. A filter support slide includes two apertures and is adapted to support different sizes of filter elements over the apertures. In the particulate detector mode, the slide carries a pair of filter elements through which a fuel sample has been passed, wherein one filter element bears particulates from the sample. A particulate detection circuit includes an incandescent light and a photocell, between which the slide is moved to introduce one filter element and then the other, whereby a differential reading of their respective opacities is obtained and displayed. In the free water detector mode, only one aperture of the slide is used to carry a chemically treated water filter pad.

Abstract: A mixture is prepared by mixing carriers to which a substance specifically reacting on an object substance adheres with a sample containing the object substance. The mixture is irradiated by light having an intensity gradient to concentrate the carriers at and near the irradiated positions by the optical pressure of the light. The efficiency of an agglomeration reaction of the carriers is thereby increased. A qualitative or quantitative measurement of the object substance is performed by detecting a state of agglomeration of the carriers within the mixture.

Abstract: A portable fiber optic detector that senses the presence of specific target chemicals in air or a gas by exchanging the target chemical for a fluoroescently-tagged antigen that is bound to an antibody which is in turn attached to an optical fiber. Replacing the fluorescently-tagged antigen reduces the fluorescence so that a photon sensing detector records the reduced light level and activates an appropriate alarm or indicator.

Abstract: A magnetic field separation system includes a magnet unit having first and second pole members forming a linear gap with a relatively high magnetic field density therebetween. A flow chamber comprised of first and second optically transparent slides mounted so as to define a generally planar fluid pathway therebetween, passes a biological fluid over the linear gap at an angle, with flow through the pathway being accomplished by gravity and capillary action. Biological fluid, when sensitized to magnetic reaction, passes through the fluid pathway, thereby resulting in perceivable separation of the sensitized particles.

Abstract: A gas sample collection device and method for cold trapping individual gas bands from a gas source that may include a chromatographic separation and for spectrographically analyzing the individual gas bands. The device includes a vacuum chamber containing a rotatably supported highly thermally conductive transmissive substrate having a highly thermally conductive support axle and at least one transmissive surface for holding a sample deposited thereon. A gas inlet is provided for depositing a mixture of sample and matrix material on the transmissive surface which is maintained at a sufficiently low temperature to cause solidification of the gas. A first set of optical elements directs an incident beam of electromagnetic analytical radiation from a source onto the solidified deposit, while a second set of optical elements directs the portion of incident beam transmitted through the deposit and substrate to a detector that is sensitive to the spectral wavelengths being investigated.

Abstract: A method and apparatus are disclosed for the in vivo and in vitro detection and measurement of dose critical levels of DNA-binding anti-cancer drug levels in biological fluids. The apparatus comprises a laser based fiber optic sensor (optrode) which utilizes the secondary interactions between the drug and an intercalating fluorochrome bound to a probe DNA, which in turn is attached to the fiber tip at one end thereof. The other end of the optical fiber is attached to an illumination source, detector and recorder. The fluorescence intensity is measured as a function of the drug concentration and its binding constant to the probe DNA.Anticancer drugs which lend themselves to analysis by the use of the method and the optrode of the present invention include doxorubicin, daunorubicin, carminomycin, aclacinomycin, chlorambucil, cyclophosphamide, methotrexate, 5-uracil, arabinosyl cytosine, mitomycin, cis-platinum 11 diamine dichloride procarbazine, vinblastine vincristine and the like.

Abstract: An efficient and reliable method and a system are proposed for detecting colored foreign particles in a white or light-colored powdery product such as a polyvinyl chloride resin with an object of product inspection and quality control. The method comprises the steps of eliminating static electricity from the powder, e.g., by spraying ethyl alcohol, continuously feeding the powder at a controlled rate on to a belt conveyor to form a uniform powder layer having a flat and even surface thereon, bringing the powder layer below a reflection-type laser-beam scanning detector projecting a laser beam with scanning and receiving the reflected beam and monitoring the output signals coming out of the detector.

Abstract: Apparatus for analyzing aerosols in essentially real time includes a virtual impactor which separates coarse particles from fine and ultrafine particles in an aerosol sample. The coarse and ultrafine particles are captured in PTFE filters, and the fine particles impact onto an internal light reflection element. The composition and quantity of the particles on the PTFE filter and on the internal reflection element are measured by alternately passing infrared light through the filter and the internal light reflection element, and analyzing the light through infrared spectrophotometry to identify the particles in the sample.

Abstract: The invention relates to an arrangement for measuring the concentration of gaseous and/or vaporous components of a fluid mixture by means of light absorption such as by means of an infrared absorption by utilizing a membrane which is made of a material in which the component of the fluid mixture to be measured accumulates. The membrane is transparent to the measuring radiation and is selectively permeable for the particles of the compounds to be measured. The membrane further acts on the radiation path between the light source and the detector. The arrangement is improved with respect to selectivity and the detection sensitivity. This is achieved in that the membrane is mounted in the flow path of the fluid mixture such that the flow path is subdivided into two component paths at the surfaces of the membrane.

Abstract: A monodisperse aerosol generator forms a stable jet of liquid at a velocity allowing columnar breakup into droplets of uniform size and spacing. To prevent degradation of the monodisperse aerosol, it is disposed by entrainment in a high velocity gaseous stream. To provide an interface for direct injection onto a particle collection device or into an infrared or Raman spectrometer or to interface a liquid chromatograph with a particle collection device or an infrared or Raman spectrometer, the generator is followed by a desolvation chamber operation at about atmospheric pressure and a multistage pressure reducer which evacuates solvent vapor and gaseous medium to form a high momentum, solvent-depleted solute aerosol beam which is input into the infrared or Raman spectrometer.

Abstract: An improved aethalometer (10) having a single light source (18) and a single light detector (20) and two light paths (21, 22) from the light source (18) to the light detector (20). A quartz fiber filter (13) is inserted in the device, the filter (13) having a collection area (23) in one light path (21) and a reference area (24) in the other light path (22). A gas flow path (46) through the aethalometer housing (11) allows ambient air to flow through the collection area (23) of the filter (13) so that aerosol particles can be collected on the filter. A rotating disk (31) with an opening (33) therethrough allows light for the light source (18) to pass alternately through the two light paths (21, 22). The voltage output of the detector (20) is applied to a VCO (52) and the VCO pulses for light transmission separately through the two light paths (21, 22 ) are counted and compared to determine the absorption coefficient of the collected aerosol particles.

Abstract: The present invention provides a device for the real time measurement of the content of an aerosol in a gas.The device performs the measurement on the basis of a sample of the gas and comprises enlargement means able to condense on the sampled aerosol, a vapor of a liquid, so as to obtain droplets of a solution of the aerosol in the liquid, impaction means, able to spray droplets onto a support provided for collecting at least one known fraction of these droplets, means for the continuous analysis of the thus collected droplets, said analysis means being specific to the aerosol the content of which is to be measured and able to supply information relative to said content and electronic means for processing the information and able to determine the content on the basis of said information.

Abstract: Effluent from a liquid chromatograph (LC) is deposited onto a deposition medium having a deposition surface inert to the LC effluent elevated above and parallel to a planar IR reflective front surface, preferably driven so as to define a continuous sample track in a generally circular, spiral or raster pattern. In the preferred embodiment, the deposition medium is a plate of germanium inert to aqueous and nonaqueous solvents, thicker than the longester IR wavelength of interest and having an undercoating of aluminum. Effluent is preferably deposited in a spiral pattern on the deposition medium in the form of a rotating disk. After collection, the reflection spectra can be interrogated by Fourier transform IR spectroscopy. The same collection technique can be used to collect and mount samples for mass spectrometry. To promote solvent evaporation, the effluent discharge is enveloped by a stream of heated nitrogen, particularly beneficial for reversed phase chromatography.

Abstract: A method for placing individual living cells at identifiable locations is provided comprising the steps of:(a) providing a carrier having a plurality of apertures, the apertures being arranged in an ordered array and being sized to hold individual cells;(b) applying a fluid containing living cells to the carrier; and(c) applying a force to the cells to move the cells into the apertures.

Abstract: The invention provides improved methods and unique instrumentation for the detection and for the quantitation of chemical substances and has particular application for the detection and for the quantitation of immunological substances.

Abstract: An arrangement for measuring diffusing particles has at least one monochromatic radiation source and a light measuring device, as well as at least one material limited particle-permeable indicator chamber provided with an optical fluorescent indicator which is optically changeable by the particles to be measured, and a carrier body having a surface which is arranged to face an eyelid and has depressions in which the indicator chambers are arranged.

Abstract: This invention relates to a spectrophotometer that detects the types and amounts of certain chemical elements dissolved or suspended in a liquid or gas medium. A light beam of desirable frequency emitted from a light source passes through the mass concentration boundary layer adjacent to a filter surface, which filter functions as a selective barrier selectively blocking chemical elements or impurities under detection from moving thereacross. Prior to the start of a measurement, the filter surface is washed with the sample medium to be analyzed by allowing the sample medium to flow parallel to the filter surface without flowing across the filter. The measurement starts at the moment the outlet of the washing flow is shut-off whereupon a light sensor such as photoelectric sensor records the intensity of the light beam passing through the mass configuration boundary layer.

Abstract: An electro-optical liquid detector assembly comprises a transparent substrate attached at its front surface to a portion of the interior surface of a wind-shield where the exterior surface of the wind-shield is wiped by a wiper blade, a light emission element assembled within the substrate to emit luminous rays towards the wind-shield thereby to cause internal reflection of the luminous rays between the interior and exterior surfaces of the wind-shield, a light receiving element assembled within the substrate to receive the incident luminous rays reflected by the exterior surface of the wind-shield and to produce an electric signal indicative of an amount of the incident luminous rays, a transparent resilient sheet member interposed between the interior surface of the wind-shield and the front surface of the substrate, and a hoder fixedly mounted on a stationary member adjacent the periphery of the interior surface of the wind-shield to support the substrate thereon and press it towards the interior surface o

Abstract: Apparatus and method for near real-time in-situ monitoring of particulates and vapors contained in fluids. Initial filtration of a known volume of the fluid sample is combined with laser-induced dielectric breakdown spectroscopy of the filter employed to obtain qualitative and quantitative information with high sensitivity. Application of the invention to monitoring of beryllium, beryllium oxide, or other beryllium-alloy dusts is demonstrated. Significant shortening of analysis time is achieved from those of the usual chemical techniques of analysis.

Abstract: An image-forming apparatus equipped with an optical means, an electrostatic image-forming means and a control means. The optical means projects a scanned light beam to be controlled according to an image to be formed. The image-forming means receives the scanned light beam projected from the optical means and forms an image corresponding to the scanned light beam. The control means controls the optical means and the image-forming means.

Abstract: An improved method of producing a deposit of particles from a liquid medium carrier on a substrate for subsequent optical analysis of the particles, involves feeding the liquid medium carrying the particles to the substrate via a flexible tube which is not subjected to fluctuating lateral compressions. The invention has particular relevance to the making of Ferrograms from wear debris in a sample of machine lubricant.

Abstract: A measuring system for the detection of particles in a gas flow utilizes a light source, a light detector for receiving light from the light source, and an evaluating circuit connected to the light detector. A hollow body having a longitudinal portion and a side portion which branches off from the longitudinal portion at an angle is provided. One end of the longitudinal portion is open for entry of the gas flow and an end of the side portion is open for exiting of the gas flow. The other end of the longitudinal portion is closed with a cover in which the light source and light detector means are arranged. Particles which might be present in the gas are deposited on inner walls of a bore hole in the cover so as to change detected intensity of the light from the light source which passes through soiled areas at the inner wall of the bore hole.

Abstract: A plate for use in an immunological analysis on the basis of agglutination reaction of particles, has formed therein a number of reaction vessels each having a conical bottom surface. The plate is formed by molding of chemically resistive acrylic resins. Each vessel has an inclined bottom surface and a plurality of concentric protrusions or depressions are formed in the bottom surface to allow formation of a stable basic layer of settled particles, which basic layer can assure the formation of clear and precise particle patterns on the bottom surface.

Abstract: Device for liquid flow cytophotometer including a device for hydrodynamic focussing (4,6) of a cell- or particle-suspension towards a measuring area, and an optical excitation-and detection-system (9), preferentially based on oil immersion optics, characterized by the focussing device being formed at or in relation to the system's optical axis-rotating nozzle assembly (1) directed towards a surface (7) which is open in relation to the surrounding atmosphere and situated on the optics (9), forming the optics' measuring area, thus supplying a laminar liquid flow of the above-mentioned suspension.

Abstract: Disclosed is a monolayering device comprising a cell sensor arrangement for receiving a liquid suspension of cells and for controlling the number of cells passing through to an application vessel, a filter tape having the application vessel positioned thereabove at a first station, a vacuum source for sucking the liquid of the liquid suspension from the application vessel through the tape, a tape moving arrangement for moving the portion of the tape having the cells deposited thereon from the first station to a second station whereat a slide is positioned, and a sponge having a fixative therein mounted on a block for biasing the tape against the slide so that the cells will adhere to the slide.

Abstract: A method and apparatus for determining the saturation temperature of a given substance dissolved in a solution under test, based on the principle that the change in the temperature of the solution causes a specific change in the amount of light being passed through the solution. The accuracy of the determination of saturation temperature is augmented by passing a preheated air through an empty space formed between the test cell and the air seal glass thereby precluding otherwise possible formation of dew-condensation on the air seal glass. This invention is characterized by forming a thin layer of fine crystals of the substance deposited fast on the bottom face of the test cell and pouring the solution onto the thin layer in the test cell.

Abstract: A method and apparatus to detect the toner concentration of two component dry developer comprising toner and carrier includes the use of a toner catcher having a conductive member and which is capacitively charged. The developer is applied to the catcher, which traps the toner to determine the toner content.

Abstract: A toner concentration control device comprises a toner supply mechanism for supplying a toner to a developing device, a probe for picking up the toner in the developing agent after development is effected and a control mechanism for controlling the toner supply mechanism. The probe has parallel grooves on the outer peripheral surface thereof which constitute a toner pickup surface. An amount of toner picked up is optically detected and the control mechanism controls the toner supply mechanism based on the result of detection. By so doing, an amount of fresh toner corresponding to an amount of toner spent by development is supplied from the toner supply mechanism to a developing agent in the developing device to maintain constant the toner concentration in the developing agent in the developing device.

Abstract: A method and apparatus for sampling and optically measuring a selected characteristic of flowing granular material in which an optical window located at one end of a hollow sight tube is disposed in the material stream at an angle with respect thereto. A dam is carried by the sight tube downstream of the window to retard material flow and cause material to collect on the window surface. The selected material characteristic may then be measured as a function of an optical characteristic of the material as viewed through the sight tube and window. An air nozzle is disposed adjacent the window to remove the collected material sample at the end of a measurement sequence.

Abstract: Eggs of Schistosoma species in urine are reliably counted in a simple field test involving passing a urine sample of 10 ml or less through a thin transparent microporous membrane having pores of less than about 30 .mu.m, drying the membrane until ready for counting, wetting the membrane with a drop of saline solution, scanning the membrane at about 40X magnification and counting the eggs. Workers of limited skill can run a test in about 1 minute.

Abstract: An apparatus for analyzing the size distribution and quantity of small particles in an aerosol comprises at least one smooth filter bearing a reflecting coating and means for measuring the change in reflectance due to the deposition of intercepted particles. At least one additional filter contains linear pores extending substantially normal to the filter surface and has a negligible transmission outside the pores. Also realized are means for measuring the change in transmission due to the retention of particles in and around the pores.

Abstract: A method and apparatus for producing a suspension of biological cells of a predetermined density (or cell spacing) on a substrate. Illumination incident upon the cell suspension is modified by the cell suspension to form a characteristic diffraction pattern. A portion of the diffraction pattern is detected at at least one off-axis location with respect to the axis of the incident illumination. The thickness of the cell suspension is reduced and the changes in the characteristic cell diffraction pattern are observed until a predetermined pattern is achieved, at which point the reduction in thickness is terminated.

Abstract: A method and structure capable of treating body fluids with cells therein for facilitating examination of cells. The body fluid sample is placed in a cylinder at one end of which is a filter, and then treating liquids are drawn into the cylinder through the filter while also being discharged out of the cylinder through the filter so that it is possible to carry out washing steps for washing out of the sample undesired components therein as well as placing in contact with the cells which are subsequently to be examined staining solutions, for example, so that a thorough staining is achieved. Thereafter the specimen remaining in the cylinder is placed on a slide and examined under a microscope.

Abstract: An optical analyzer (10) wherein a sample (19) of particulate matter, and particularly of organic matter, which has been collected on a quartz fiber filter (20) is placed in a combustion tube (11), and light from a light source (14) is passed through the sample (19). The temperature of the sample (19) is raised at a controlled rate and in a controlled atmosphere. The magnitude of the transmission of light through the sample (19) is detected (18) as the temperature is raised. A data processor (23), differentiator (28) and a two pen recorder (24) provide a chart of the optical transmission versus temperature and the rate of change of optical transmission versus temperature signatures (T and D) of the sample (19). These signatures provide information as to physical and chemical processes and a variety of quantitative and qualitative information about the sample (19).