Abstract: A slide motion sampling valve for use with a particle study device and carrying an expansive type microsyringe having a minimum trapped volume. The sampling valve is formed of a slidably movable member carrying a trapping volume, an expansive element and ejection port in the form of a fine aperture, and a stationary element sealingly engaged with said movable member and carrying an opening leading to the entrance of the sheath flow arrangement. The valve operates between a conditon where the ejection port and the opening are aligned and a condition where communication to the entrance is blocked whereby to isolate the trapping volume from said entrance except during ejection of the predetermined amount. One embodiment described employs a linear sliding motion while another embodiment employs a rotating sliding motion.

Abstract: A method and apparatus for jetting a measured volume of a suspension of particulates such as blood cells or colloids into a single fluid-primed incompletely partitioned transducer chamber in such a way that the dynamic relationship between the priming liquid and the inflowing jet imparts to the suspended particulates the properties of a stable stream line monofile which reliably traverses one or more particulate-identifying and/or analyzing sensing zones. Said transducer chamber has one or more of the following three sources of energy for moving the contained fluids: an easily maintained non-critical pressure differential between the suspension inflow port and an exit line, potential energy stored within the transducer chamber during the priming step, a pump mechanism to propel particulate-free fluid. The measurement period in all such transducers may be defined by monitoring the volume of either the inflowing or displaced outflowing liquid.

Abstract: The interfacial tension in a liquid-liquid system is determined by estimating the flow rate of the heavier liquid as it is discharged under constant head through a capillary immersed in a body of the lighter liquid, or conversely, of the lighter liquid as it is discharged under constant head through a capillary immersed in a body of the heavier liquid. A known voltage is applied to each drop which forms at and detaches from the capillary tip and an electrometer is used to measure the total electrical charge per drop and the frequency of drop formation/detachment. The determination is made under conditions in which a plot of interfacial tension versus the square of the applied voltages yields two straight lines whose slopes of .+-.C/2 where C is the capacitance of the interface per unit area and the positive value is generated from the positive polarity voltage and the negative from the negative polarity.

Abstract: In an apparatus for counting ions, a double-collector electron multiplier comprises a first and a second collector for receiving secondary electrons from an exit end of a dynode member of the electron multiplier. The first and the second collectors have a first and a second electron receiving surface, respectively, wherein the second electron receiving surface has a narrower area than the first electron receiving surface. A first and a second amplifier are separately used in amplifying a first and a second electric current produced from the first and the second collectors, respectively. An ammeter is connected through a switch selectively to the first and the second amplifiers to provide a selected measuring range for the number of ions which enter the electron multiplier.

Abstract: A measuring apparatus for measuring the number and size of impurities such as dust and bacteria in super-pure water includes a sealed container; a sample supply line which sealingly interconnects a source of super-pure water with the sealed container and supplies a sample mixture of super-pure water and electrolyte to the sealed container; an overflow pipe which sealingly connects with the side of the sealed container; a negative electrode which extends into the sample mixture in the sealed container; a hollow sensor which extends into the sample mixture in the sealed container, the hollow sensor containing a positive electrode surrounded by electrolyte and having a small hole at its lower end; and a detecting circuit connected to said negative and positive electrodes for supplying a certain DC current therebetween and detecting voltage pulses caused by impurities passing through the small hole into the hollow sensor.

Abstract: A dust detector ring assembly for detecting extremely small quantities of particulate contamination in air being taken into the carburetor of an engine is disclosed. The assembly includes a series of infrared light emitting diodes alternately interposed with a like series of infrared light detecting diodes and arranged in a circle around an interior surface portion of a frame defining a passageway of circular cross-section therethrough. A light beam generated by each of the emitters is directed against a different one of the detectors so that the light beams intersect one another at a common point in the passageway. The sensitivity of the assembly is thus greatest at the common point of intersection of the light beams and decreases proportionally moving away from the intersection point toward the defining surface of the passageway. A flexible circuit board is formed in a circle and is connected to the emitters and detectors. A flat circuit board is connected to the circular circuit board.

Abstract: A flow cytometer has an aperture in which an inlet chamber and/or an outlet chamber have predetermined geometric relationships with respect to the aperture for decreasing electronic edge effects and increasing the sensitivity of electronic particle volume measurements. In one embodiment, the aperture is triangular and is formed by assembling a plurality of truncated pyramids with their truncated surfaces defining aperture walls. At least one of the elements forming the aperture walls is either part of a lens system or a transparent cover plate so that simultaneous optical and electronic cell volume measurements can be performed. On one embodiment, a piezoelectric transducer is provided to sonically clear any aperture clogging.

Abstract: A method of counting red blood cells suspended in a blood sample is disclosed which can judge the presence or absence of clogging in the sample passage system of a blood cell counting apparatus. In this method, for example, the counting of red blood cells for a period of 200 msec is repeated 50 times, the means value X and standard deviation SD of 50 red blood cell counts each indicating the number of red blood cells per unit time (equal to 200 msec) are calculated, and when one of the red blood cell counts deviates from the mean value X by more than 3SD, such deviation is judged to presage clogging in the sample passage system. Further, each of the red blood cell counts can be displayed on the fluorescent screen of a CRT display.

Abstract: An electrical pulse apparatus for measuring impurities in ultrapure water includes a deaeration device connected to the conduit line supplying electrolyte to the hollow detector so as to deaerate the electrolyte and enable bubbles formed by electrolysis at the electrodes to be readily redissolved and thus increase measurement sensitivity and speed.

Abstract: A particle analyzing apparatus and method of moving and counting particles in suspension through such an apparatus. The particle analyzing apparatus comprises a particle counting device wherein particles in suspension are caused to be moved through an aperture whose effective impedance is changed with the passage of each particle therethrough and a fluid connection means for drawing a quantity of the suspension through the aperture, including a source of vacuum. The source of vacuum comprises a bellows having an end, and a constant force means connected to the end of the bellows means.

Abstract: A system that is particularly useful in biological fluid analysis includes a face plate member and a mating flexible member, one of which has a plurality of passages. Selected motion of the flexible member provides a valving action to control fluid flow into, through, and out of the passages. An analysis chamber in a surface of the face plate member is in fluid communication with a passage and has an analyzer which, for a hematology analyzer, is preferably an impedance-type particle counter.

Abstract: A combined gap and stripline monitor device (10) for measuring the intensity and position of a charged particle beam bunch in a beam pipe of a synchotron radiation facility. The monitor has first and second beam pipe portions (11a, 11b) with an axial gap (12) therebetween. An outer pipe (14) cooperates with the first beam pipe portion (11a) to form a gap enclosure, while inner strips (23a-d) cooperate with the first beam pipe portion (11a) to form a stripline monitor, with the stripline length being the same as the gap enclosure length.

Abstract: A diesel smoke meter which uses micro-waves to detect the density of black smoke contained in the exhaust gas discharged from the diesel engine through an exhaust pipe. A micro-wave transmitting device is coupled to the exhaust pipe and transmits micro-waves into the exhaust pipe. Micro-waves transiting the exhaust pipe are attenuated by the black smoke in the exhaust gas. A micro-wave receiving device receives the attenuated micro-waves and provides a received signal which varies in accordance with the signal level of the attenuated micro-waves. A measuring device receives the received signal and provides an output indicative of the density of black smoke in the exhaust gas.

Abstract: During a predetermined measuring time there are generated electrical pulses in a detector arrangement, each of these electrical pulses corresponding to a respective particle which is to be counted. The pulse amplitude of the electrical pulses corresponds to the particle size. In a discriminator circuit the electrical pulses are compared with a threshold value. Those pulses, the pulse amplitude of which exceeds the threshold value, are inputted to a counter circuit and a time measuring circuit for measuring the total time duration of the electrical pulses. All of the electrical pulses are delivered to a further counter circuit and a time measuring circuit. The digital values derived from both counter circuits and both time measuring circuits are infed to a digital computer in which there is computed according to the equation Z.sub.T *=(Z.sub.S -Z.sub.E).multidot.T.sub.S /(T.sub.S -T.sub.E) a count result Z.sub.T * for the pulses, the pulse amplitude of which does not exceed the threshold value.

Abstract: The interfacial tension in a liquid-liquid system is determined by estimating the flow rate of the heavier liquid as it is discharged under constant head through a capillary immersed in a body of the lighter liquid. A known voltage is applied to each drop which forms at and detaches from the capillary tip and an electrometer is used to measure the total electrical charge per drop and the frequency of drop formation/detachment. The determination is made under conditions in which a plot of interfacial tension versus the square of the applied voltages yields two straight lines whose slopes of .+-.C/2 where C is the capacitance of the interface per unit area and the positive value is generated from the positive polarity voltage and the negative from the negative polarity.

Abstract: The invention provides a new method and apparatus for the detection of non-conductive particulates in molten metals, such as aluminum, gallium, zinc and lead, that can be liquified and drawn into a suitable refractory container. The passage into the container is of very small diameter (about 300 micrometers for aluminum) and it forms part of a current path between two electrodes carrying a current of about 1 to 500 amperes. The path is surrounded by liquid metal which forms an effective Faraday cage screening the path, enabling the passage of a particulate of about 15 micrometers or larger to produce a voltage pulse between the electrodes of greater than 5 microvolts, which is detectable above the inevitable background noise, which is of about that value.

Abstract: A particle analyzing apparatus for studying a stream of membrane-sheathed particles in liquid suspension wherein, for a given particle, a first particle pulse signal is obtained from a first sensing aperture having a first low frequency electrical field with an intensity below that causing particle electrical breakdown; a second particle pulse signal is obtained from a second sensing aperture having a second low frequency electrical field with an intensity equal to or greater than that causing particle electrical breakdown; a third particle pulse signal is obtained from one of the sensing apertures by having a high frequency electrical field therein or, alternatively, from a third sensing aperture having a third low frequency electrical field with a second and different intensity equal to or greater than that causing particle electrical breakdown.

Abstract: Flat beam optical sensing performed transverse of a flow aperture, of the particles passing through the aperture, directly indicates the presence of individual particles in the aperture. The indication can be used to eliminate or otherwise modulate the coincidence errors resulting in particle measurements taken through the length of the aperture.

Abstract: An apparatus for analyzing particles, adapted to operate continuously even in the absence of particles contained in a sample medium, includes a sensing region and a particle analyzer associated therewith. A fluid flow path, preferably air flow, causes a sample medium with particles therein to flow through the sensing region. Another fluid flow path ensheathes the sample medium with a flowing sheath fluid for hydrodynamically focusing the particles as they pass through the sensing region. The sheath fluid is adapted to flow at a first flow rate compatible with the flow rate of flowing particles. When the apparatus is operating in the absence of a sample medium, the sheath fluid is controlled to flow at a second flow rate, slower than the first flow rate, for collection thereof.

Abstract: A transducer for measuring particles suspended in a fluid is disclosed. The transducer includes an elongated tubular member having a particle-free fluid conducting channel and an aperture for permitting the flow of a particle containing fluid into the fluid conducting channel. The size of the particles is measured by measuring the impedance variation of the particle containing fluid as it passes through the aperture. Spurious variations of the impedance caused by reentry of the particles into the region about the aperture is prevented by spacing the wall of the channel opposite the aperture so that the particle containing fluid impinges thereon after passing through the aperture and so that the particle-free fluid transports the particles away from the aperture before the particles reenter the region about the aperture.

Abstract: A particle size distribution analyzer includes a detector adapted to detect particles by electrical or optical differences from a medium containing the particles in dispersion and generate signals proportionally to the sizes of the detected particles, a threshold circuit adapted to remove noises or fragmental signals from the detected signals so as to obtain pulse widths at a constant position, a gate circuit adapted to decide the passage or non-passage of the particles through the threshold circuit, a counter circuit adapted to count the number of the particles fed from the gate circuit, a memory connected to the counter circuit, an arithmetic circuit connected to the memory and the detector, a controller circuit connected to the gate circuit, the memory and the counter circuit, and means for displaying or recording the data stored in the memory.

Abstract: A hematocrit measuring instrument of the type which determines hematocrit of blood from the electrical resistivity of the blood is provided with a blood resistivity measurement device, an ultrafilter for filtering a part of the plasma from the blood, a filtrate resistivity measurement device for measuring the resistivity of the filtrate from the ultrafilter and an arithmetic circuit for calculating the hematocrit of the blood from the resistivities of the blood and the filtrate. The hematocrit measuring instrument is connected into a circulatory path for the blood outside of the patient's body and continuously measures the hematocrit of the blood from the resistivity of the blood and the resistivity of the filtrate from the ultrafilter.

Abstract: A suction chamber and at least one sample chamber are located in relatively shiftable operating adjacency. The suction chamber may have a plurality of orifices and the sample chamber a single port for selective registration with the orifices. On the other hand, the suction chamber may have a port or an orifice, and a plurality of sample chambers may have either respective ports or orifices, and the chambers mounted for relative shifting for effecting selective port/orifice registration. A sample depletion detector may be provided in association with the sample chamber. The sample chamber may have a minimum volume residual sample well for maintaining a filled system with the suction chamber to facilitate recurrent sample analyzing function.

Abstract: A manometer is provided for metering samples of fluid flowing in devices wherein particle concentration in the fluid is being counted or measured. Such devices include particle counters for determining blood cell concentration in body fluid. The device includes low permeable stretchable diaphragms in the device connections for containing the mercury therein, and a slide valve in the vent connection to restrict the movement of the mercury during storage or shipment. The arrangement herein includes, also, a one-way valve downstream of the "stop" point to stop flow substantially immediately upon the cessation of the measurement interval to reduce unwanted airflow to the counting aperture. A start and stop arrangement in the mercury flow path for causing the leading edge of the mercury meniscus at the axis thereof to engage the electrode contacts includes simple wire tips extending into the mercury flow path to the axis thereof for engaging the axis of the mercury meniscus.

Abstract: A method and apparatus for determining the size distribution of certain particles, of a particular composition, such as iron sulfide (pyrites), in a sample of host material, such as coal. Data representative of the amount of at least one predetermined elemental constituent of the particles is obtained for each of numerous similarly-sized subsamples of the sample. The "constituent amount" data for each subsample is sorted into bins, each representative of a respective constituent amount range in a series of constituent amount ranges. Respective scaler representations of the fraction of the constituent amounts, represented by each bin range, are provided to yield an approximate representation of the distribution function of the amounts of the constituent in the subsamples of the coal. Those scaler representations collectively may provide a histogram.

Abstract: New and improved method and apparatus for the correction of coincident errors attendant the automated detection and counting of mixed particles having detectable characteristics of different levels in particle counting applications wherein the detection of "dominant" particles under coincident particle conditions, renders undetectable the "dominated" particles, with resulting inaccuracy in the "dominated" particle count. Such inaccuracy is corrected by modifying the "dominated" particle count in accordance with the time duration of the signals which are generated attendant the detection of the "dominated" particles.

Abstract: A method of and means for controlling orientation of particles through a sensing zone in a particle analyzing system, which facilitates particle shape determination, comprises laminar flow orientation of the particles in a stream moving through an elongate straight passage coaxially aligned with an elongate sensing zone longer than the longest particle to be sensed and analyzed. The particles are carried through the sensing zone in an isokinetic laminar flow sheath of fluid.

Abstract: An automatic apparatus for measurement of the number of cells or particles in suspension in a liquid medium during fermentation, comprising a preparation unit for the measurement, a measurement receptacle mounted for vertical translation, a device for drawing in the liquid to be measured which is provided with oleopneumatic regulation, electronic circuits and measuring, processing and visualizing members wherein, the active members being connected for their operation to a pneumatic automatic device assuring the completely automatic operation of the assembly.

Abstract: A particle analyzer wherein a flow of liquid suspension, having individually entrained particles, flows along a predetermined path; a center pair of electrodes are positioned on opposed sides of the predetermined path: the center electrodes are energized to provide an electrical sensing field therebetween, two pairs of outer electrodes are positioned so that one pair is on each side of the center electrodes; the outer electrodes are oriented and/or energized so that their electrical fields bulge outward in the direction of the sensing field of the center plates to narrow the width of the sensing field along the predetermined path. Additionally, the field between the center plates can be focused in additional directions and the sensing electrode arrangement can be implemented in a flow cell, with or without an aperture, or on the surface of a substrate.

Abstract: An electron beam system for non contact testing of three dimensional networks of conductors embedded in dielectric material, specifically detection of open and short circuit conditions. Top to bottom and top to top surface wiring is tested electrically without making physical electrical contact. The system comprises two flood beams and a focus probe beam wih one flood beam located at either side of the specimen. Proper choice of acceleration potentials, beam currents and dwell times of the beams allow alteration of the secondary electron emission from the specimen in such a way that electrical properties of the conductor networks can be measured directly. The difference in secondary electron emission resulting from different surface potentials is detected as a strong signal which allows clear discrimination between uninterrupted and interrupted as well as shorted pairs of conductors.

Abstract: A system of testing the continuity of electrical conductors extending through an insulating layer without contact. A flood gun irradiates one side of the body to charge the exposed conductors to a given potential. A steerable electron beam scans the front side to generate secondary electron emission from those conductors. The secondary emission is enhanced from conductors with conductivity between front side and back side as a result of the surface potential established by the rear flood beam. The secondary emission varies depending on the state of continuity in the three dimensional network of conductors and produces signals at the detector which allow clear discrimination between uninterrupted and interrupted conductors. The system is applicable for unfired ceramics where contact destroys the specimen.

Abstract: Disclosed is an abnormal pulse detector for use with a particle analyzing apparatus of the Coulter.RTM. type for generating discrete particle pulses in response to liquid suspended particles passing through a sensing aperture, the abnormal pulse detector comprising: a bad pulse detector for generating a bad count pulse for each of the particle pulses which have a width that is either too long or too short, comparative pulse detector means for generating a comparative count pulse for each of the particle pulses or for each of the particle pulses not generating a bad count pulse, counter and comparator circuitry for counting the bad count pulses and the comparative count pulses and for obtaining the ratio of the bad count pulses to the comparative count pulses so as to indicate a alarm condition when the ratio reaches a predetermined, unacceptable level.

Abstract: A particle analyzer for a sample suspension of particles originating in a container in which: a flow director is mounted between the container and a first chamber, a particle sensing aperture is mounted between the first chamber and a second chamber, a liquid sheath is introduced into the first chamber for hydrodynamically focusing the particles through the sensing aperture, an electrical current passes through the sensing aperture for generating impedance signals, the pressure drop is regulated across the flow director to assure a constant flow of the suspension through the flow director and the aperture, and the flow director is formed into an optical element for viewing the sensing aperture.

Abstract: Methods and apparatus for monitoring the condition of dielectric fluid used in EDM are described. A continuous sample of dielectric liquid is withdrawn from a tank containing the EDM electrode and workpiece and is passed between electrodes of a capacitance cell before being returned to the tank. The capacitance between the electrodes gives an indication of the amount of metal particles resulting from EDM in the dielectric liquid. In another arrangement a magnetic field is used to direct most ferrous particles through a capacitance cell or part of a capacitance cell while most non-ferrous particles pass through another cell or another part of the cell. Measurement of the capacities of the cells or parts of cells provides an indication of the relative amounts of ferrous and non-ferrous particles in the dielectric liquid.

Abstract: The invention provides a device and method for measuring the volumes of oil (310) and water (320) in an oil and water mixture (300) wherein the mixture (300) flows at a constant volumetric flow rate. The device includes a formed cylindrical passageway (200) capable of receiving the fluid mixture (300) and for separating the fluid mixture (300) into separate oil and water droplets (310, 320) while maintaining the constant volumetric flow rate. Electrical probes (400) mounted across the passageway (200) are interconnected with an alternating current source (1200) to apply current to the flowing oil and water droplets in the passageway (200). The resulting sinusoidal voltage pulses (1300, 1310) produced by the flowing oil and water droplets are compared to a predetermined voltage level (1320) and if a water droplet (320) passes the probes (400), the sinusoidal voltage pulses (1310) exceed the predetermined level (1320) and these pulses are then counted (1240).

Abstract: Apparatus for counting platelets and red blood cells in a whole blood sample includes an aperture type transducer. Alarm techniques are provided for indicating defects in the counting procedure due to excessive noise or red cell fragments, small (microcytic) red cells, and giant (macro) platelets.

Abstract: By subjecting cells, such as red blood cells, to a hypotonic solution or a solution having a lytic agent, the cells will rapidly attain a change in volume and electrical resistance parameters, which change is measured as a function of time, for example, by a Coulter Counter.RTM. particle measuring instrument. The relationship between the change in the cell resistance or cell volume and the time of immersion in the volume changing solution provides a discriminator between a normality, different diseases, and certain inherited differences.